Question

# The American Journal of Political Science (Apr. 2014) published a study on a woman's impact in mixed-gender deliberating groups. The researchers rando

Study design
The American Journal of Political Science (Apr. 2014) published a study on a woman's impact in mixed-gender deliberating groups. The researchers randomly assigned subjects to one of several 5-member decision-making groups. The groups' gender composition varied as follows: 0 females, 1 female, 2 females, 3 females, 4 females, or 5 females. Each group was the n randomly assigned to utilize one of two types of decision rules: unanimous or majority rule. Ten groups were created for each of the $$\displaystyle{6}\ \times\ {2}={12}$$ combinations of gender composition and decision rule. One variable of interest, measured for each group, was the number of words spoken by women on a certain topic per 1,000 total words spoken during the deliberations. a) Why is this experiment considered a designed study? b) Identify the experimental unit and dependent variable in this study. c) Identify the factors and treatments for this study.
a) A designed study (experiment) deliberately imposes some treatment on individuals in order to observe their responses. An observational study tries to gather information without distribing the scene they are observing. Since each group was given a treament of gender composition and decision rule, a treatment was deliberately imposed on the experimental units and thus the study is a designed study. b) The experimental units are the individuals on whom an experiment is perfomed. $$\displaystyle\text{Experimental unit=Subject in the study}$$ A response variable (or dependent variable) is a variable that measures an outcome or result of a study. $$\displaystyle\text{Response variable=Number of words spocen by women per 1000 total words spoken during deliberations.}$$ c) The factors are variables whose levels are manipulated by the experimenter and thus these variables are controlled by the experimenter. $$\displaystyle\text{Factors=Gender composition, Decision rule}$$ The treatments are what the subjects are subjected to. The treatments are the 12 combinations of gender composition and decision rule in this case. $$Treatments=0\ females\ -\ Unanimous,\ 1\ female- \ Unanimous,\ 2\ females\ -\ Unanimous,\ 3\ females\ -\ Unanimous,\ 4\ females\ -\ Unanimous,\ 5\ females\ -\ Unanimous,$$
$$0\ females\ -\ Majority\ rule,\ 1\ female\ -\ Majority\ rule,\ 2\ females\ -\ Majority\ rule,\ 3\ females\ -\ Majority\ rule,\ 4\ females\ -\ Majority\ rule.\ 5\ females\ -\ Majority\ rule.$$