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BayesiaLabPrevious ReleasesBayesiaLab 5.0.4Analysis (5.0.4)Direct Effects (5.0.4)

Direct Effects (5.0.4)

We have added a new analytic function that consists of analyzing the effect of a variable on the Target variable, while all other variables are held fixed.

Example Marginal Probability Distributions

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Example Total Effect

  • 1 on Pleasure has a (total) effect of +0.821 on [Factor_1].

The posterior probability distributions of the other associated variables also change at the same time as a result of the input.

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Example - Direct Effect

  • 1 on Pleasure while holding all the other associated variables fixed has a (direct) effect of +0.297 on [Factor_1], which is very different from the total effect.
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Report

We have extended the Total Effects analysis with the Direct Effects analysis, by automatically fixing the probability distributions of the variables, except:

  • The Not-Observable variables belonging to the Class “Factor”
  • The variables belonging to the Class “Non Confounder”
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Direct Effect:

Dex=δyδxDe_x = \frac{\delta_y}{\delta_x}

Standardized Direct Effect:

SDex=δyδx×σxσySDe_x = \frac{\delta_y}{\delta_x} \times \frac{\sigma_x}{\sigma_y}

Contribution:

Cx=∣SDex∣∑xi∈xa∣SDexi∣C_x = \frac{\lvert SDe_x \rvert}{\sum_{x_i \in x_a} \lvert SDe_{x_i} \rvert}

Elasticity:

Ex=δy/(maxy−miny)δx/(maxx−minx)E_x = \frac{\delta_y/(max_y - min_y)}{\delta_x/(max_x-min_x)}

Note that the contribution C is computed only for the nodes specifically selected for the this analysis.

Quadrants

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Direct Effect

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Standardized Direct Effect

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Target Direct Effect Analysis

The contribution values can be directl shown as labels on the corresponding arcs

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Once again, the contribution is computed for the selected nodes only. Selecting only one node would lead to a contribution value of 100%.

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Target Mean Analysis

We also have extended the Target Mean Analysis with the Direct Effects to allow graphing the Direct Effect Function

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The Direct Effect is the derivative of the Direct Effect Function computed at the a-priori mean value (delta = 0)

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Target Dynamic Profile

We also have extended the Target Dynamic Profile with the Direct Effects

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Analysis (5.0.4)Multi Quadrant Analysis (5.0.4)