Making Sense of the Social World 4th Edition Chapter 6, Causation and Experimental Design

Empirical association Temporal priority of the independent variable Five criteria should be considered when trying to establish a causal relationship. Empirical association Temporal priority of the independent variable Nonspuriousness Identifying a causal mechanism Specifying the context in which the effect occurs Chambliss/Schutt, Making Sense of the Social World 4th edition © 2012 SAGE Publications

Empirical Association The independent variable and the dependent variable must vary together. A change in X is associated with a change in Y. ΔX ΔY Chambliss/Schutt, Making Sense of the Social World 4th edition © 2012 SAGE Publications

Temporal Priority of the Independent Variable The change in X must occur before the change in Y. ΔX ΔY t1 t2 Chambliss/Schutt, Making Sense of the Social World 4th edition © 2012 SAGE Publications

Nonspuriousness We say that a relationship between two variables is spurious when it is due to variation in a third variable; so what appears to be a direct connection is in fact not. X ΔX ΔY ΔZ Chambliss/Schutt, Making Sense of the Social World 4th edition © 2012 SAGE Publications

A Causal Mechanism A causal mechanism is the process that creates the connection between variation in an independent variable and the variation in the dependent variable it is hypothesized to cause. Chambliss/Schutt, Making Sense of the Social World 4th edition © 2012 SAGE Publications

The Context in Which the Effect Occurs No cause has its effect apart from some larger context involving other variables. When, for whom, and in what conditions does this effect occur? A cause is really one among a set of interrelated factors required for the effect. Chambliss/Schutt, Making Sense of the Social World 4th edition © 2012 SAGE Publications

True Experiments Have at Least Three Features That Help Us Meet These Criteria Two comparison groups (in the simplest case, an experimental group and a control group), to establish association. Variation in the independent variable before assessment of change in the dependent variable, to establish time order. Random assignment to the two (or more) comparison groups, to establish nonspuriousness. Chambliss/Schutt, Making Sense of the Social World 4th edition © 2012 SAGE Publications

But being able to claim causality makes all that hard work worth it! Research designs that allow us to establish these criteria require very careful planning, implementation, and analysis. But being able to claim causality makes all that hard work worth it! Chambliss/Schutt, Making Sense of the Social World 4th edition © 2012 SAGE Publications