Does the order someone receives A and B matter?

****Helpful for the paper ****

· Mental Rotation Task

· Shepard and Metzler stimuli[3] will be presented in pairs

· In each trial, the two stimuli will either be the same but in two different orientations, or will be mirror images of each other.

· Experimental Conditions:

· Matching –

· Subjects will be instructed to determine if the two figures presented in each trial are the same or different

· Stimuli will be either the same but rotated from one another (by 40-, 80-, 120- or 160- ) or different from one another.

· Compare –

· Subjects will be instructed to determine if each of two images that are not rotated into a different orientation from one another are the same or different

· Subjects will be instructed to press their thumb for same judgments and their forefinger for different judgments.

· Primary behavioral measures are accuracy of judgment

· Experiment Order

· Independent Variable

· 2 levels

· No-motivation group

· Motivation group (motivation =candy)

· Dependent Variable

· Change in accuracy score on the mental rotation task

· Instructions

· Half participants during practice phase (both groups) given Version A of mental rotation task and half given Version B – Trial 1

· Remember each has a compare and rotate condition

· Break –

· Control group: “Now that you’ve had some practice doing this I want you to complete this one”

· Experimental group/Motivation group: “Now that you’ve had some practice doing this I want you to complete this one, depending on how well you do you will receive candy”

· Participants are given the opposite version from one they first received – Trial 2

· Papers collected

· All participants given Candy

· Experimental Design

· Two-groups

· Between-subjects design

· We will use the change scores between Trial 1 & Trial 2

· What statistics should we use?

· Two groups – between subjects

· 1 dependent variable score

· INDEPENDENT t-Test

· Things we can also consider

· Are the versions differing in difficulty and that is impacting the score?

· Do a t-test between version A an B before motivation/not instructions

· Does the order someone receives A and B matter?