m odeling the m ind and the m ilieu : computational modeling for organizational psychologists
TRANSCRIPT
"MATHEMATICS IS THE LANGUAGE WITH WHICH GOD HAS WRITTEN THE UNIVERSE." -- GALILEO GALILEI
Mathematics has not tended to be the language of theories in psychology and organizational science Math models need to be solved, but often seen as
intractable when describing human or organization behavior Computational models do not need to be solved
Computational models are algorithmic descriptions of process details, typically operationalized as computer programs that are dynamic and can be simulated (Taber & Timpone, 1996) JAP has only published one computational model, ever
(Vancouver, Weinhardt, & Schmidt, 2010) 0.3% of AMJ articles are computational models in last 11 years, only 1.3% of AMR articles included
computational models (nearly all macro or meso)
YET, COMPUTATIONAL MODELS:
Increase precision and transparency Less ambiguity of concepts and explanations Specific predictions (compared to natural
language theories) Assure internal (logical) consistency
Model works Accounts for phenomena claimed
Identify unanticipated consequences Simulations can lead to new findings
DYNAMICALLY CHALLENGED
Human ability to predict values in dynamic variables is low (even among those in STEM fields) Dynamic variables are variables with memory
Stocks, levels
Predicting the behavior of dynamic, nonlinear processes, interacting subsystems Forget about it
HINTZMAN (1990)
“To have one's hunches about how a simple combination of processes will behave repeatedly dashed by one's own computer program is a humbling experience that no experimental psychologist should miss” (p. 111).
OBJECTIVES: BY THE END OF THIS WORKSHOP YOU WILL KNOW HOW TO …
Identify a problem worthy of modeling Define the system to be modeled Build a model Evaluate a model
STEP 1: IDENTIFY PROBLEM
Dynamic phenomena All phenomena?
Existing theory Lot’s of talk, no models
Existing computational architectures Neural networks Systems dynamics Cybernetics
STEP 2: SYSTEM DEFINITION
Unit(s) of analysis Individual in context
Problem boundary: just enough Core dynamic processes
Restrictions Time frame (100 days)
Variables: add as needed
Well-Being
Importance
Coping
Physical and SocialEnvironment
Perception
Desires
Discrepancy
PART OF EDWARD’S THEORY OF STRESS AND WELL-BEING
STEP 3: BUILDING THE MODEL
Vensim System Dynamics platform (Forrester) Units often organizations or other larger systems Coopting for psychological modeling
Individual cognitive processes Individual in context
Open software Model setting: Unit of time; “Days”
Menu Sketch Tools
Main Toolbar
Output File Window
Simulation
Analysis Tools
Build Window (Where you build your model)
Lock Move Variable Level Variable
Arrow Rate Shadow Variable
InputOutput
Comment Delete Equation
Reference
SKETCH TOOLS
KEY VARIABLES IN THE MODEL
Variable NameType of Variable Time
Person/ Environment
perceptions Endogenous Time-varying Person
Environmental States Endogenous Time-varying* Environment
actions/coping behavior Endogenous Time-varying Person
discrepancies Endogenous Time-varying Person
desires Exogenous Constant (0) Person
Well-Being/Job Satisfaction Endogenous Time-varying* Person
importance Exogenous Constant (1) Person
TYPES OF DESIRES
Optima: Not too much; not to little Minima: Only values exceeding desire a
problem (e.g., budget) Maxima
Hard maxima: values exceeding desire ignored Soft maxima: more is better, but with
diminishing returns
STEP 4: EVALUATING THE MODELSimulations that worksPostdictionAssess assessment strategies
Will past designs and analysis have been diagnostic?
Hypothesis generation and testingStrong inference via model
comparisonDiffering predictionsModel fitting
Complexity (# parameters) vs. fit
DON’T MARRY YOUR MODEL!
Questions?
Further information: ORM tutorial: Vancouver, J.B., & Weinhardt, J.M., (online).
Modeling the mind and the milieu: Computational modeling for micro-level organizational researchers. Organizational Research Methods.
Modeling in Org Psych: Weinhardt, J. M. & Vancouver, J. B. (in press). Is there a computational model in your future? Only the math will tell. Organizational Psychology Review.
Symposium: Understanding Dynamics Conceptually, Analytically, Computationally, and Empirically. Tuesday, Aug 7 201211:30AM - 1:00PM. Boston Park Plaza, Beacon Hill Room.
Web site: https://sites.google.com/site/motivationmodeling/home
Help from: Justin Weinhardt; Mike Warren; Amanda Covey; Justin Purl; Xiaofei Li