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BayesiaLab 5.0: New Features
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Data |
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| New format for arc constraint dictionary | The new format is: name of the arc's starting node or class, -> , <- or even -- to indicate the both possible orientations, name of the arc's ending node or class. | ||||
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| Disambiguation of the names of classes, nodes and states in the dictionaries | In order to specifically differenciate a name which is the same for a classe, a node or a state, you must add at the end of the name the suffix "_c" for a class, "_n" for a node and "_s" for a state. | ||||
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| BOM taken into account when exporting dictionaries | As the dictionaries are saved in UTF-8 format, on Windows systems, a Byte Order Mask is needed at the beginning of the file. It can be written or not according to the convenient option int the settings: Settings>Data>Save Format. | ||||
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| State virtual number dictionary | Dictionaries of state virtual numbers can be imported or exported. The syntax is: Name of the node Equal, Space or Tab virtual number of states or empty if we want to delete an already existent number. The state virtual number is an empty string or an integer superior or equal to 2. A node can be present only once otherwise the last occurrence is chosen. |
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| Local structural coefficient dictionary | Dictionaries of local structural coefficients can be imported or exported. The syntax is: Name of the node Equal, Space or Tab value of the local structural coefficient or empty if we want to reset to the default value 1. The local structural coefficient is an empty string or a real number superior to 0. A node can be present only once otherwise the last occurrence is chosen. |
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| Rearranging dictionaries | The menus used to import and export dictionaries has been rearraged in three submenus each:
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| Database report | A database report can be generated via the contextuel menu of the icon in the status bar.It contains two parts. The first part is a global summary analysis of the database: It shows the number of variables, the number of variables with missing values and the number of variables with continuous values associated. The global database is analyzed and the number of examples is indicated. If the database has stratification on a node, it is also indicated with the corresponding probability distribution. The sum of weights and the normalization factor of the weights are displayed if database has associated weights. The report indicates the number of missing values and if the database has row identifers. If the database has data types associated, the learning and test databases are also analyzed. For each one, the example number, the sum of the weights and the number of missing values are shown. The second part of the report details the content of the database for each variable: For each discrete or continuous variable, the numbers of missing values and filtered values with their associated percentages are displayed if necessary. For the continuous variables, the report indicates if they have associated continuous values. It indicates also the minimum, the maximum and the mean of each continuous variable. All this information is displayed for the global, learning and test databases if data types are associated. |
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| Choice of unnecessary columns when associating database |
The button Unmatched Columns displays all the columns in the database that are not in the network. The following dialog is displayed and allows the user to distribute or not the selected columns:
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| Row identifier |
A new type of column is available when a database is imported or associated: setting a column of the database as row identifier allows defining an identifier for each row. Identifiers can be of any type (string or numbers) but cannot contain missing values. However, unicity is not required. Two rows can have the same identifier. These identifiers will be saved with the database and kept in any derived database (generated by some analysis or tools). This identifier can be used to select a line in the database that will be observed (during Interactive Inference, Interactive Updating or manual selection on the database). The current identifier is displayed in the status bar. |
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| Information about the other types of columns | In import/associate, a new line has been added in the information panel in order to indicate the number of data type, weight and row identifier columns. | ||||
Network |
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| Costs greater or equal to 1 | Now, all the costs associated to the nodes must be greater or equal to 1. If not, the corresponding nodes are considered as not observable. | ||||
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| Select nodes with missing values |
The menu Edit>Select Nodes>Missing Values allows selecting the nodes having a percentage of missing values greater than a given threshold:
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| Select nodes with assessments |
The menu Edit>Select Nodes>Assessments allows selecting the nodes having assessments. |
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Learning |
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| K-Means Clustering |
The menu Learning>K-Means Clustering allows clustering data in an unsupervised way thanks to the k-means clustering algorithm, in order to find partitions of homogeneous elements. Originally used only on real variables, this algorithm is extended to use also discrete variables. Before running the k-means clustering, the user must select the variables on which he wants to apply the algorithm. These variables can be either continuous or discrete but not hidden (i.e. without associated data). Once selected, the clustering tries to regroup the data into a chosen number of clusters in which each observation belongs to the cluster with the nearest mean. It is similar to the expectation-maximization algorithm for mixtures of Gaussians in that they both attempt to find the centers of natural clusters in the data as well as in the iterative refinement approach employed by both algorithms. The values of the selected nodes used by the clustering algorithm are computed as following:
In all cases, the filtered values are skipped and the data are standardized. If there are missing values in the database for the selected variables, the corresponding rows are skipped and not used for the clustering. The weights associated to the chosen rows are taken into account. Once finished, a node Clusters is created with each state corresponding to each cluster found by the algorithm. The data corresponding to the created node Clusters are added in the database. A missing value is put for the node in each row containing missing values for the selected variables. The following dialog box allows entering the wanted number of clusters. Of course this number must be superior or equal to 2:
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| New parameters for Taboo learning |
It is possible to define the size of the taboo list as well as the maximum numbers of parents and children allowed. If these options are not checked, they are not taken into account. In addition to standard options, it is possible to maintain the current structure of the network to start learning. |
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| New parameters for Taboo Order learning |
It is possible to define the size of the taboo list and to maintain the current structure of the network to start learning. |
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| Structure equivalent example number for each learning algorithm |
For each learning algorithm there are startup options indicating that all arcs will be deleted before learning and allowing the user to define a Structure Equivalent Example Number, i.e. a virtual database with the indicated size representing the current structure: |
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| Keeping learning parameters |
For each parametrized learning algorithm, the chosen parameters are saved in the network and can be reused later in various tools. |
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Inference |
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| Observed mean/value |
Now, a target mean/value can be set as an evidence for a node. When a node has values associated with states or is a continuous node or has numerical states, it is possible to choose a target mean/value for this node. An algorithm based on MinXEnt allows determining a probability distribution corresponding to this target mean/value, if this distribution exists. Of course, the indicated target value must be greater than or equal to the minimum value and less than or equal to the maximum value.
Once the target value entered, there are three options:
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| Fixing current probabilities | It is possible to quickly fix the current probability distributions of the selected nodes by using the contextual menu of the monitors. All the selected nodes will have their own current marginal probabilities as fixed probabilities. Only node with no evidence or soft evidence are concerned. | ||||
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| Relaxing probabilities | It is possible to quickly unfix the probabilities of the selected nodes with observed probability distributions by using the contextual menu of the monitors. The corresponding nodes become soft observed. This is done on all selected monitors. | ||||
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| Causal inference |
In addition to the standard exact inference, it is possible to make causal inference, ie to consider a set of nodes as causal nodes in the Bayesian network. Until a node defined as causal has no evidence set, it behaves like a classical node. However, once evidence set, the node is actually causal: relationships with potential parents are deleted. To consider a node as causal, just click on the menu Intervention in the monitor's contextual menu in validation mode. In this case, the monitor node becomes blue like a decision node. If evidence has already been set on this node, it will be automatically removed.
Once the mode of observation used is set to Intervention, the node is defined as causal and it is possible to set all possible kinds of evidence. Once evidence set on the node, the network is mutilated and the node takes the form of a square as the representation of a decision node. In the next image, the node Smoking has been defined as causal by clicking on the menu Intervention, but it has not yet been observed. He behaves therefore as a normal node: Once the node Smoking has evidence, it loses its relationship with its parent and is represented as a square: To transform a causal node into classic, simply click on the menu Observation in the monitor's contextual menu. If an evidence has been set on this node, it will be automatically deleted. Nodes defined as causal are taken into account in any analysis. |
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| New database save dialogs |
In the various database save dialogs (save database, batch tools with current database, etc.), the user can choose the part of the database (learning, test, all) he wants to save, if a data type is associated. The number of selected nodes is displayed if any. In this case, the user can choose to save in the file only the selected nodes or all of them. In addition, the user can choose to save the long name of the states and the associated continuous values.
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| Selecting database rows with identifier |
In validation mode, if the database has row identifiers, a shift + right-click on the database icon
This panel is also displayed in interactive inference and interactive updating with a database when the user performs a right-click on the textfield. |
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Analysis |
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| Variation editor for analysis |
Several analysis like Target Optimization, Target Optimization Tree, Target Interpretation Tree, Target Interpretation Tree and Target Dynamic Profile need to define positive and negative variations in order to apply them on the mean of each node. The following editor allows the user to edit these variations. This editor is accessible from the parameter panels of the concerned analysis. It is possible to associate with each node a negative and a positive variation in percentage. These variations will be saved with the network and will be available for each analysis. A variation, positive or negative, is a positive real number between 0 and 100%. The default value is 10%. ImportThe Import button allows importing a list of variations from a dictionary as in Associate Dictionary menu.
Export The Export button allows exporting the list of negative and positive variations in a dictionary as in Export Dictionary menu. |
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| Upgrade of target dynamic profile |
The target dynamic profile has been dramatically upgraded. The modifications and additions are explained below: Criterion Optimization: Search Method:
In each case, the variables' filtered states will never be used. Stop Criterion: |
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| Target optimization tree |
This function allows searching for several policies in order to optimize the target node. Two options are available:
Its functionning is similar to the target dynamic profile except that instead of finding only the "optimal policy" it tests also alternative optimization policies.
For each branch, the search is done again on the remaining nodes with the same rules until one of the stop criterions is obtained or no more node is available. The filtered states are not taken into account in the search. The following panel allows entering all the parameters: TargetYou can select the target node. By default, the current target node is used. After that, you can choose to optimize the selected target state or the mean. Criterion Optimization:You can choose to maximize or minimize the criterion. Several search methods are available:
The settings panel allows restricting the search with four different stop criterions that can be combined.
The results will be associated as evidence scenario file. Each branch of the tree corresponds to a line of evidence in the evidence scenario file. If an evidence file is already associated, you can choose to replace it or to append the examples at the end. ResultsThe results are displayed in a binary tree. Each node of the tree represents the node chosen by the algorithm. The evidence context will be displayed at the top if necessary. A node contains four parts:
Two kinds of branches exist:
The toolbar at the top of the window allows the user:
The buttons at the bottom of the windows allow closing the window, saving the image, printing the tree and displaying the report. The contextual menu allows:
It is possible to perform a manual zoom by clicking and dragging the mouse to select the area that will be zoomed in. The shortcut ctrl + mousewheel performs zooming (and unzooming) on the tree centered on the cursor. Moving the mouse over a node displays a tooltip containing the chain of evidence done until this node. A double-click on a node closes its subtrees in the window. Double-click on it to display them again. Report:Depending on the options, the button Report displays an html report containing the list of the best chosen nodes in the whole tree with their best observation and the corresponding optimization score. |
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| Target interpretation tree |
This function allows generating a tree that helps interpreting the target node. The algorithm optimizes the knowledge of the target by reducing its corresponding entropy (or binary entropy if we choose a specific state with the "Center on State" option). We are then using the (binary) mutual information to build the tree (that can be combined with the cost associated to the nodes). The Adaptive Questionnaire is functionally close to that tree. If the user always choose the first variable, the sequence of the questionnaire is described in that tree. For each branch, the search is done again on the remaining nodes with the same rules until one of the stop criterions is obtained or no more node is available. The filtered states are not taken into account in the search. The following panel allows entering all the parameters: TargetYou can select the target node. By default, the current target node is used. After that, you can choose to center the search on a specific state or not. Search MethodSeveral search methods are available:
A checkbox allows taking the cost of the evidence into account during the search by dividing the score based on the mutual information. The observation context is also taken into account during the analysis. Search Stop Criterions:The settings panel allows restricting the search with three different stop criterions that can be combined.
The results will be associated as evidence scenario file. Each branch of the tree corresponds to a line of evidence in the evidence scenario file. If an evidence file is already associated, you can choose to replace it or to append the examples at the end. Results:The results are displayed in a binary tree if the mean variations are used or in a n-ary tree if hard evidence is used. Each node of the tree represents the node chosen by the algorithm. The evidence context will be displayed at the top if necessary. Nodes are very similar to monitors. A node contains four parts:
If hard evidence is used, the name of the observed state is displayed on the branch. If the mean is observed, the value of the mean of the chosen node is displayed. If this mean corresponds to the negative variation, it is displayed in red, otherwise, if it is the positive variation, it is displayed in blue. ToolbarThe toolbar at the top of the window allows the user:
The buttons at the bottom of the windows allow closing the window, saving the image and printing the tree. The contextual menu allows:
It is possible to perform a manual zoom by clicking and dragging the mouse to select the area that will be zoomed in. The shortcut ctrl + mousewheel performs zooming (and unzooming) on the tree centered on the cursor. Moving the mouse over a node displays a tooltip containing the chain of evidence done until this node. A double-click on a node closes its subtrees in the window. Double-click on it to display them again. |
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| Kolmogorov-Smirnov test in network global performance |
The K-S test has been added in the network global performance when the network has learning and test databases. It is the test of distribution adequacy between the two samples. This test is only computed in the comparison panels. It compares the two distributions of log-likelihoods. The values Z, D and the corresponding p-value are displayed. |
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| Extract database in global performance |
In the result panel of the network global performance, a button Extract Database allows extracting the data on which the computed log-likelihood is inside a given interval. The parameters are:
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| Fix reference in influence analysis |
In the Influence Analysis wrt the Target Node a checkbox Fix References becomes available if Inverse Influenceis selected. It allows keeping the value of the a priori probability (red line) as reference if new evidence is set on the monitors. When this option is chosen, a priori is replaced by reference in the caption. This option is also available when data are used. The computed delta values take into account the reference probabilities as well. |
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| Arc's mutual information |
The mutual information is computed for each arc of the network (from the Analysis menu or the shortcut J). It takes into account the filtered states. The thickness of an arc is directly proportional to the mutual information. Three values are displayed in the arcs' comments:
You can use the slider to change the arc display threshold:
If all the arcs of a node became transparent, the node becomes transparent. |
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| Filtered values taken into account in mutual information |
Now the filtered values are taken into account when mutual information is computed (Target Dynamic Profile, Optimization Tree, Interpretation Tree, Relationship Analysis, Target Analysis, etc.). |
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| Colored borders in influence analysis |
In influence analysis, the borders now take the color of the corresponding nodes. Those colors are displayed if the button used to Display Colored Tags of nodes is pressed in the main toolbar. |
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| Translucent nodes skipped in analyzes |
Now, in all analyzes, the translucent nodes are skipped. |
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| Filtered states skipped in target report |
In the target report, filtered states of the dependent nodes are skipped in the analysis. |
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| Translucent arcs skipped in relationship analysis |
In the relationship analysis, if some arcs are translucent, because one of their nodes is translucent, they are not analyzed. |
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| Hidden variable discovery |
This report allows computing the G-test and the independence probability between two variables of the network bounded by a path of length one or two and which is not a V-structure (Analysis menu). All the existing paths of length one or two (without V-structure) will be tested. The independence probability will be computed and only the paths which are not dependent are kept in the report. Computing independence between variables:
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| Target optimization |
The target state optimization has been transformed to become the target optimization. It is now possible to optimize a state of a node or the mean of a node. This can be done in the Target section. The parameter dialog allows choosing to export the results in an evidence scenario file in the Output section At the end of the analysis, a dialog indicates that the analysis has ended. |
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| Probability analysis wrt the target state |
This analysis report is available for any target node (by the Analysis menu). It allows computing the impact on the target state when slightly modifying one propability of a node's CPT.
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Monitors |
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| New menu Monitor |
A new menu Monitor has been added to the menu bar. This menu is only visible in validation mode. It contains several items which are the same as in the contextual menu of the monitor panel and in the monitor toolbar. |
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| Log-likelihood in monitor information panel |
Now, the log-likelihood corresponding to the current evidence is computed and displayed in the monitor information panel. |
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| Sorting monitors |
Two menus has been added to the menu Monitor and the contextual menu of the monitor panel:
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| Fitting the monitor's size |
Two menus has been added to the menu Monitor and the contextual menu of the monitor panel:
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| Scientific notation |
In addition to the option in the settings, the menu Display Probabilities with Scientific Notation is added to the menu Monitor and the contextual menu of the monitor panel. It displays the probabilities in scientific notation in the monitors and in the monitors' tooltips. This option is saved with the network. |
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| Tooltip with extended values int the information panel of the monitors |
Values in the information panel are displayed in the tooltip with a greater number of decimals. |
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| Fix and relax probabilities |
Two menus has been added to the contextual menu of the monitors:
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| Display properties saved |
The various display properties of the monitors are now saved with the network. |
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Interface |
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| Three state stop button |
The task progress bar thus has three states:
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| Colored names in reports |
Now, in the various html reports, the cells displaying the name of a node have a background color which is the node's color (if any). |
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| Colored line plot |
A new graph is available: the colored line plot. This graph displays the colored line plot of the two selected variables. The continuous variable is displayed along y-axis. The indices of the values in the database are along x-axis. The color variable gives the color of the curve for each index. Parameters: Select a continuous variable in the first combo-box and a variable for the color in the second combo-box. Graph: The black lines represent the limits of the vertical node's intervals. When you move the mouse over the graph, the information in the top panel is updated. It displays the coordinates of the cursor in the graph. The total number of displayed values is also indicated. If you click inside a point (or several if the points overlap), a dialog appears containing the rows of the database corresponding the selected points.
You can perform a zoom on the graph by pressing the left button, drag the mouse and then releasing the button: the selected area will be magnified. To remove the zoom, double-click on the graph, the default view will be restored. |
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| Layer intersection |
The checkbox Intersection displays only the nodes contained in all the selected classes. |
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| Import/Export in property editors |
It is now possible to import and export dictionaries of properties in the editors of costs, constants, temporal indices, local structural coefficients and state virtual numbers. |
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| Sortable tables in property editors |
It is now possible to sort the columns of the tables in the editors of costs, constants, temporal indices, classes, local structural coefficients, state virtual numbers, mean variations and forbidden arcs. Simply click on the header of the column you want to sort. |
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Knowledge Elicitation |
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| Assessments |
The mechanism of knowledge elicitation of BayesiaLab allows a set of experts to provide assessments on the conditional probability tables of nodes. A "facilitator" can mediate to ask relevant questions to experts and get their assessments. The experts must be declared in the network with the expert editor. Two ways of capturing the assessments are proposed:
When a node has assessments, the icon A slideshow explains the principle of knowledge elicitation in BayesiaLab. It can be found at the following address: Assessments can be entered from the tab Probability Distribution in the node editor. Experts must have been already created. In this case, a button Assessment is displayed and becomes activable when a cell is selected. After pressing the button, the assessment edition is done for the selected line. When an assessment was made for a line in the conditional probability table, the corresponding cells have a green border. Move your mouse over a cell displays a tooltip showing:
The assessment editor displays the list of assessments for the selected line of the conditional probability table. A line in this table defines an assessment. This assessment consists of:
The button Add adds an assessment by default at the end of the list. This assessment will then be edited manually. It is possible to have several assessments from the same expert, but, for clarity, it is not recommended. The button Delete deletes the selected assessments. When an assessment is selected the expert's image is displayed on the right side: Assessment ValidationWhen you press the button Accept of the dialog box, assessments are automatically normalized if necessary, the sum of probabilities to be equal to 100. |
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| Experts |
The assessment mechanism needs to define experts associated with the network. An expert is defined by:
In the editor expert, these four properties can be edited by double-clicking on the corresponding cell. The fifth property displayed is the number of assessments the expert has made in the network. This property is not editable. The table can be sorted by clicking on the column headers. AddThe button Add opens a new window allowing the user to enter information about a new expert:
To add or change the image, simply click in the box. The verification of the uniqueness of the name is made during the validation. RemoveThe button Remove the selected experts of the list. The assessment done by this expert will also be removed from the nodes. However, the conditional probability tables won't be regenerated. ImportThe button Import allows loading a dictionary of experts. The format of the dictionary is the following:
The button Export exports a dictionary of experts. The images of the experts will be saved in png format in the same directory as the dictionary with the name expertImageN.png Open Session:The button Open Session allows opening an online assessment session.
The user msut provide a session identifier (unique) and a password. If a session with the same name has already been opened, a dialog box will offer to overwrite if this session comes from the same machine. If it comes from another machine, it will not be possible to use this session name. Close Session:the button Close Session allows ending the current online assessment session. This button is active if at least one expert is selected. It generates conditional probability tables of the nodes by taking into account the assessment of selected experts. If none of the selected experts has made assessment for a node then the consensus of all experts is used. The credibility of experts is used for generation When at least one expert is associated with the network, the indicator |
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| Online assessment editing |
When an online knowledged elicitation session has been created, a button Post Assessment is displayed in the window. When you press this button, the current question is posted online so that experts can answer it connected via a dedicated web interface. This question asks the experts to get the probability distribution that corresponds to the chosen line of the conditional probability table.
This table can be sorted by clicking on the header of each column. Web InterfaceOnce the online session has been opened, an expert can connect with its Internet browser to following secured address: He will enter his expert name and the name of the session respecting upper case: Once connected, the waiting interface will be displayed: Once a question is posted through BayesiaLab, it will appear in the interface of each expert. If the expert has already answered this question, the corresponding fields are already filled. They may be modified if necessary. On the right side, the name and the comment of the node are displayed. A colored slider and a field allows editing the probability associated with each state the node. The expert can also enter the confidence it grants to its assessment. A text field lets you enter the comment associated with this assessment. On the left, the context of the question is displayed, i.e. the current states of each parent of the node. By hovering the name of the parents, their comments will be displayed in a tooltip. The pie chart in the bottom left reproduces the current probability distribution. The button Validation sends the anwser of the expert to the server then the indicator of experts who have answered is updated on BayesiaLab. After that, the waiting interface is displayed again. |
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| Assessment tools |
The contextual menu of the expert indicator The menu Tools > Assessment provides access to various tools for exporting assessments. The menu Analysis > Graphic provides access to the assessment sensitivity analysis. |
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| Assessment sensitivity analysis |
This tool allows, through sampling, visualizing graphically the impact of the different assessments of network's variables on each state of target variables. This tool is close to the parameter sensitivity analysis. The following dialog box lets you choose the parameter nodes and target nodes and to indicate the number of samples to be used: The icon Three policies are available for sampling:
In each case, if there is no expertise that matches the sample, then the consensus is used. For each target node, the result of the analysis is presented with a curve representing the repartition function of the probabilities of each state, and, a bar chart representing the probability density function. Besides these graphical results, the mean and the standard-deviation of the probabilities of the target states are also given. The user selects the node and the state to see by clicking on their tabs. In this example, we have 32% chance that the state "Weak" of the node "TARGET" has a probability between 70% and 72.5%. The analysis is performed over the whole nodes or over a subset of selected nodes. The translucent nodes are not taken into account. The context of the evidences is taken into account and displayed under the graphs. A contextual menu allows displaying the comment associated with the nodes instead of the name and also the long names of the states. It allows copying the chart as an image. |
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| Assessment report |
This report is generated from the contextual menu of the expert icon in the status bar. It contains two parts. The first part is a global summary analysis of the assessment: It shows the list of experts: their name, credibility, comment and the number of assessments done like in the expert editor. The last column shows the average assessment time used by each expert to make assessment. This time is computed only when an online session is used. After that, two tables are displayed:
The global and maximum disagreements between the experts allow us to easily find on which nodes the knowledge of the experts is not the same and the knowledge elicitation should be verified. The second part of the report details the assessment for each variable: For each node with assessment, a table contains:
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Tools |
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| Exporting assessments |
A submenu Assessment is available only if experts are registered on this network and assessments have been done. It gives access to:
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| Shuffle on data in cross-validation |
In cross-validation tools, data are shuffled before slicing the database in order to avoid biases due to ordered data. |
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| Joint comparison |
This tool is used to compare the joint probability distributions from two different files. These files have been previously generated by the Batch Joint Probability keeping only the computed joint probability in the destination file. This analysis is similar to the Global Network Performance but on the joint probabilities present in the input files. The files must be indicated in the following panel:
For each panel, the mean, standard deviation, minimum, maximum and computed row numbers are indicated below the chart. In a first time, each file of joint probabilities is analyzed separately and after that the comparison is done. The Kolmogorov-Smirnov Test is computed to mesure the distribution adequacy between the two samples. this test is present in the comparison panels only. It compares the two distributions of log-likelihoods. The values Z, D and the corresponding p-value are displayed. |
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| Structural coefficient modified in cross-validation |
In cross-validation tools, the structural coefficient of the reference network is recomputed for the generated networks by multiplying it with final learning weight divided by the inital learning weight. |
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| Database stratification in cross-validation |
In cross-validation tools, if the initial databse is stratified, the generated databases will be also stratified with the same parameters. |
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| Structural coefficient analysis |
The menu item Tools>Cross validation>Structural Coefficient Analysis allows computing a frequency value that measures how robust is each arc. The network needs a database and the validation mode must be activated.
For analysing the structural coeficient, the chosen learning algorithm will be tested with different values of the structural coefficient in a given interval. At each iteration, the network structure is learned on entire database with a growing structural coefficient. ParametersSimply select the learning algorithm we want to use, and indicate the minimum and maximum limits for the structural coefficient and the number of iterations to perform in the following dialog box: The structural coefficient can vary from 0 to 150. Three options are available allowing computing at each iteration:
The tested structural coefficients will vary from the given minimum to the maximum by step of (maximum - minimum) / number of iterations. An output directory can be specified where all networks learnt will be saved. Depending on the chosen learning algorithm, a dialog box displays specific settings:
Once the networks have been learnt on each structural coefficient, the following report is displayed: This report is similar to the Arc Confidence except for the last table where the column indicating the maximum structural coefficient of the structure has been added. This indicates, among the coefficients tested, which is the greatest that has obtained this structure. The report can be saved in a HTML format file. It can also be printed. Three other options exist: displaying graphs, extracting the network and displaying the curves. GraphsThe Graphs button from the report allows displaying the graphical structure comparator. With this tool, data contained in reports can be viewed and interpreted easily. Extracting the networkThe Network extraction button from the report displays network extraction tool. This tool allows building a network from any structure depending on arcs frequency thresholds. CurvesThe button Curves of the report allows displaying the curves corresponding to the options chosen in the parameters. A dialog box allows the user to choose the curve to display:
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| Data perturbation |
The menu item Tools>Cross Validation>Data Perturbation allows avoiding the local minima of the network's structure in which the network can be trapped. The network needs a database and the validation mode must be activated. The BayesiaLab's structural learning algorithms are based on heuristic search. Then, they can be trapped into local minima. As they are based on different heuristics, those local minima can be different. Applying every algorithms and choosing the one with the lowest score represents the first solution to optimize the obtained network. This data perturbation tool provides another solution consisting in adding noise to the weights associated to each line of the database in order to try escaping from local minima. A noise is generated by using a Gaussian law, with 0 mean and the standard deviation set by the user. The selected learning algorithm is applied on this perturbed database and the score of the final structure is computed by using the original weights. The decay factor is applied after each iteration to reduce the standard deviation. ParametersSimply select the learning algorithm we want to use, and indicate the initial standard deviation, the decay factor and the number of tests to perform in the following dialog box: An output directory can be specified where all networks learnt will be saved. Depending on the chosen learning algorithm, a dialog box displays specific settings:
Once the networks have been learnt, the following report is displayed: This report is similar to the Arc Confidence except for the last table where the column indicating the Structure's Mean Score has been added. The report can be saved in a HTML format file. It can also be printed. Two other options exist: displaying graphs and extracting the network. GraphsThe Graphs button from the report allows displaying the graphical structure comparator. With this tool, data contained in reports can be viewed and interpreted easily. Extracting the networkThe Network extraction button from the report displays network extraction tool. This tool allows building a network from any structure depending on arcs frequency thresholds. |
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| Multi-quadrant analysis |
This function can be found in the Tools menu. The network must have a database and a target node. This tool allows analysing a network having a variable called "selector" which must be different from the target node. for each state of this variable, one of the three available analysis will be performed on the variables of the network with respect to the target. The classic use of this tool is when the variable "selector" is a list of products we want to compare with each other to analyze their strengths and weaknesses relatively to the target variable. The translucent nodes are not taken into account in these analysis. For each state of the selector, the algorithm will create a network with the same structure as the original network and with a database containing only the lines corresponding to the current state. The following panel lets you define the parameters of the analysis.
The display of the results takes the form of points positioned on a 2D chart. It is similar to quadrant chart in the correlation with the target node report or in the total effects report. The points represent the variables. If a node has a color then the point will be displayed in this color. The name of the node is displayed at the right of the point. The mean value of the nodes is displayed along x-axis and the reult of the chosen analysis is along the y-axis. The chart's contextual menu allows to :
The chart above represents the value of each node according to the chosen state. When we move the mouse over a node, other nodes disappear and the values of this node for each state of the selector are displayed. In the example, the relevant node is "Tasty" for the state 8 of the selector node "Product". Other values of "Tasty" are displayed with the name of the corresponding state next to them. When choosing the option Display Scales from the contextual menu, chart displays for each node a scale between the minimum and maximum values among all states of the selector. The mean is also indicated by a vertical line. It is therefore possible to easily identify where is the value of the node for the current state among all other states. So we can identify the possible negative and positive progress margins for the current product for each of its qualities. By hovering the mouse over the point, we obstain, as previously, the different values of the node for each state in addition to the scale: The button Export Variations allows exporting the percentages of negative and positive variations of each node in order to use them in other analysis thanks to the mean variation editor. |
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Settings |
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| Variable clustering settings |
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| Managing instance reusability |
This item is visible only if your license allows it. It is also not available for Mac OS X. When an instance of BayesiaLab is already running, if the user wants to open again BayesiaLab or performs a double-click on a XBL file, the previous instance will be automatically reused. The following options allows managing this behavior:
BayesiaLab needs to be rebooted to take changes into account. |
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| Scientific notation |
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| Perspectives |
Perspectives allows the user to configure the different menus of BayesiaLab as he wants. Each menu of the menu bar is present in the column Component and can be set visible or not if the user doesn't need it. This can be done by checking of not the corresponding option in the column named Visible. It is possible to edit the shortcut of a menu by selecting the component in the list, for example Target's Optimization Tree: Once selected, the buttons and field in the bottom part become available. To remove a shortcut, select it and click in the text field. Once the focus is on the text field press the key The button Load allows importing a perspective file. The button Save allows exporting the current perspective into a text file. To validate all the changes, you must click on the Apply or Accept buttons. |
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Help |
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| Analysis of the use of BayesiaLab |
This analysis can be accessed by the menu Help > Use Analysis. With the registration of the use of each menu of the BayesiaLab's menu bar (see Perspectives), it is possible to make graphical analysis of the use of BayesiaLab's tools. The window contains in its right hand side the tree of BayesiaLab's menus. Each item can be selected and the chart of use appears in the right side as a pie chart. Pie charts can be displayed under two forms that can be selected by the options on the right:
The following figure shows the overall use of BayesiaLab, i.e. the number of functions used (red) and the number of functions never used (green). Just move the mouse pointer to display a tooltip information corresponding to the specified area. When you select a menu or submenu in the tree on the left, the graph shows, then, only the use of the selected menu and its submenus. In the following figure the Analysis menu is selected: To see the detailed chart, simply press the button Display Detailed Use which displays a window containing a larger as well as the detail of the use on the right hand side. When you click on the second option, the chart displays the number of times each function was used, according to the menu selected in the tree: To see the detailed chart, simply press the button Display Detailed Use. The right part shows for each sector the number and percentage of use compared to the sum of all uses. The button Display Table opens a new window containing the table all BayesiaLab's menus with their name, their icon, their visibility, their shortcut, and their number of uses. When a row is selected, pressing on the button help displays the help corresponding to the function, if it exists. the table is sortable by clicking on each column's header. |
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Shortcuts |
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| Changing target |
In all modes, a double-click on a node while pressing T sets the node as target with its first state as target state. In validation mode, a double-click on a probability bar of a monitor while pressing T sets the corresponding node as target with the corrresponding state as tarrget state. |
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| Exclusion of nodes |
An node can be set as excluded or not excluded by double-clicking on it while pressing X in modeling mode only. |
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| Total effects |
The default shortcut for total effects is Shift + T. |
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| Zooms |
When the focus is in the graph area (by clicking on a the background, for example), you can zoom in and out with Ctrl + Mouse Wheel. When the focus is in the monitor area (by clicking on a monitor, for example), you can zoom in and out with Ctrl + Mouse Wheel. |
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Ergonomics |
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| Windows, Linux and others |
Now BayesiaLab can be reused if it is already opened by running the program directly or by double-clicking on an XBL file. If the program is uninstalled and is currently running, BayesiaLab will be automatically closed. |
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| Mac OS X |
The Mac OS X standard application menu has been added. Moreover, BayesiaLab can be opened by double-clicking on XBL files and can be reused if it already opened. BayesiaLab now acts as other applications on Mac OS X. |
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| Setup 64 bits for Windows |
The setup file without JRE can be installed on any Windows 64 bits. Installing a 64 bits JRE before is required. |
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| Error e-mail |
The bug report mechanism now uses the default user's mailer program to send the error log. The user can modify the generated e-mail if wanted. |
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Miscellanous |
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| Analyst edition |
In addition to the standard, professional and educational editions, a new edition named analyst is now available. The analyst edition is only oriented towards network analysis. It does not contains data-mining tools. |
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in the status bar.



















To zoom in the tree
To zoom out the tree
To go back to the initial zoom
To fit the tree to the window
To display the tree horizontally











Go back to the previous threshold.
Go to the next threshold.
Store the mutual information in the comments of the arcs if those comments are displayed.
Stop analysis.



when the system is ready
when a task is in progress. The bar represents an indication of the time spent (note that time evolution is not necessarily linear or even growing). A click on the red light stops the progress of the task.
when a task is stopped. The button becomes orange while the process ends. It allows the network to go back to a correct state after having stopped the current task. At this time, the button is no more clickable until it turns green.




displayed in the cell indicates the importance of disagreement between the experts for this cell. More the icon is visible, more the disagreement is important.





is displayed in the status bar of the network. A clic on this icon displays this editor.





indicates that the node has assessments.






Warning : Use only when data is scarce when used with low structural coefficient.



















or
(not the buttons).




