Domenica DiStasio Exercise 2 Identifying one Independent Variable Designs The possible designs are Random Groups Matched Groups Natural Groups or Repeated Measures 1 A researcher wishes to test a hypothesis that left handed people will perform better than righthanded people in a mirror tracing task She locates 20 left handed people and 20 right handed people and has each trace a circle while looking in a mirror She measures the amount of time required to trace the circle a IV Handedness 2 levels left or right b DV Time to trace circle c Design Natural Groups Design 2 A researcher asks for volunteers from a large psychology lecture class to participate in a psychology experiment involving mnemonics in memory He obtains 30 volunteers Each person s name is put on an index card The cards are shuffled and put into two piles of 15 each Students whose names are in the first pile are placed in the imagery mnemonic group and those in the second pile are placed in the rote memorization group All students are presented with the same list of 20 nouns The data are gathered as the percent correct out of 20 a IV Mnemonic imagery or none b DV Percent correct out of 20 c Design Random Groups Design 3 A cognitive psychologist was interested in the effects of motivational states on performance on a visual search task She had 20 participants who were told to fast for 8 hours prior to the study She then had these hungry subjects search lists of words for a target word Each participant performed two searches For one search the target word was food related while for the other search the target word was not food related She found faster search times for food related target words a IV Motivational state hungry vs not b DV Performance on visual search task c Design Repeated Measures Design Domenica DiStasio Exercise 2 4 Twenty students with developing study skills are assigned to two different training programs Prior to assigning the students to the treatment groups a vocabulary test is given to all 20 students Students with similar vocabulary test scores are paired and then members of each pair are randomly assigned to either the first or second treatment At the end of the program the students are tested on a standardized test of study skills a IV The training program 2 levels b DV Score on test of study skills c Design Matched Groups Design 5 A researcher sets out to determine whether less formal first names such as those ending in a y or ie influence a person s judgment of friendliness Twenty subjects are each presented with 60 slides Each slide contains a different facial photo with a name typed below each photo The names are all 5 7 letters long Half of the names end in y or ie such as Susie Jimmy and Billy nicknames The other half do not end in y or ie such as Susan James and William more formal names The subjects are to rate each photo for friendliness of the person shown on a 10 point scale where 1 unfriendly and 10 wicked friendly a IV Name ending in y or ie vs not ending in it b DV Friendliness of person c Design Repeated Measures Design Bonus Question For each of the repeated measures design examples above which counterbalancing tool would you use a Latin Square or a Block Randomization Counterbalancing tool You would use block randominazation