Title MODULE 2 - SIMPLE DESIGNS .pdf ✅

7/2/25 1 EXPERIMENTAL DESIGNS 69 EXPERIMENTAL DESIGNS Classified along at least three dimensions § Number of IVs § Number of levels of IV/s § Whether the subject receives all conditions or different subjects are randomly assigned to different conditions. (repeated measures/within-subjects or randomized design/between subjects) SIMPLE RANDOM GROUPS DESIGN REPEATED MEASURES DESIGN NATURAL GROUPS DESIGN COMPLEX COMPLETELY RANDOMIZED DESIGN COMPLTETELY REPEATED MEASURES DESIGN MIXED DESIGN One IV with 2 or more levels Two/more IVs at 2/more levels MATCHED GROUP DESIGN MATCHED FACTORIAL DESIGN 70
7/2/25 2 EXPERIMENTAL DESIGNS Snodgrass et al • Same S tested in all conditions • Appropriate when exposure to one condition does not effect behavior in a subsequent condition • More sensitive : Same S serves as their own control • Ss paired on some criterion related to the DV Random Groups/ Independent Groups Design Repeated Measures Design Matched Groups Design • Different Ss tested in each condition • Appropriate when S’s behavior will be differentially altered by different conditions. • IV is selected (individual difference variable/ subject variable) Natural Groups Design If an experiment involved the use of deception which design would you use ? What are some issues that may happen with using each of these designs? 71 Activity - PAY ATTENTION TO THE WORDS ON THE SCREEN Screwdriver Confidence Tangerine Telephone Elephant Memory Hesitate Genuine Quality Excited Know Gown VioliBrave VaguPiano Stoveam Boot Luck Saw Here Ant Pig In no specific order, RECALL the words you just saw 72
7/2/25 3 CHECK YOUR RECALL WORD LIST Screwdriver Vague Quality Boot Tangerine Know Memory Pig Telephone Luck Hesitate Saw Elephant Same Confidence Stove Violin Brave Excited Gown Piano Here Genuine Ant TOTAL TOTAL TOTAL TOTAL GUESS THE VARIABLES IN THE EXPERIMENT YOU JUST DID 73 EXPERIMENTAL DESIGNS § Description: Experiments with more than 1 IV at 2 or more levels each § Why : We wish to determine the effect of each independent variable alone (main effect) and the effect of the independent variables in combination (interaction effect). § Variables: Between subjects (random groups) and within subjects (repeated measures) variable § Each level of one IV (aka a factor) is combined with each level of the other IVs to produce all possible combinations. Each combination, then, becomes a condition in the experiment. Leary ACTIVITY : An experiment on the effect of cell phone use (yes vs. no) and time of day (day vs. night) on driving ability. • How many conditions would such an experiment have ? • Can you represent this in table to show how many conditions would be there ? 74
7/2/25 4 EXPERIMENTAL DESIGNS Leary Cellphone use Yes No Time of day Day Night 2 X 2 design - E.g. An experiment on the effect of cell phone use (yes vs. no) and time of day (day vs. night) on driving ability. 1. An experiment on the effect of type of cell phone use (using a handheld cell phone, hands free cell phone, no cell phone) and time of day (day vs. night) on driving ability. 2. A researcher was interested in understanding how witnessing modelling by either a male or female helper (confederate), in emergency (car breaks down) and non-emergency (spilled cup of pencils) situations, would affect helping behavior to same race vs opposite race individuals requiring help. 3. A researcher was studying the effects of exposure to rooms using different scents (lavender, lemon, no scent) on performance of employee working in a MNC Write the design. How many conditions would there be in the expt.? 75 EXPERIMENTAL DESIGNS Leary Completely Randomized Design Completely Repeated Measures Design Mixed Design Matched Factorial Design Ps assigned randomly to one possible combination P goes through all the conditions in the expt. Aka. Between-within design or split – plot factorial design (randomly assign+ repeat conditions) Match Ps into blocks based on a criteria + randomly assign. No. of Ps in each matched block = no. of experimental conditions. 76