Topic 13- Factorial Designs

Question 1

What is Factorial Design?

Answer 1

A research study involving two or more factors

Often described by the number of its factors, such as design or a three/two factor desisgn

Question 2

How are the results of Factorial Design measured?

Answer 2

Results are analyzed in terms of identification of main effects and interations effects

Question 3

How many independant variables are there in FD?

Answer 3

two or more

Question 4

How are the factors marked?

Answer 4

By letters (A B C).

Question 5

How can factors be manipulated

Answer 5

Manipulated ( amount of caffine…)
Naturally ( age, gender)

Question 6

Between-subjects factorial designs

Answer 6

A separate group of participants for each of the treatment conditions (each person gets one treatment) our previous example is between subjects

-These types of factorial designs require a larger number of participants

-avoid order and practice effects

-minimize the resources required by each participant

Question 7

Within-subjects factorial designs

Answer 7

Single group of individuals participates in all the separate treatment conditions, (each participant gets every treatment)

-require fewer participants
-better control the influence of extraneous variables

Question 8

What are the advantages of FD?

Answer 8

-More realistic because most behaviour influenced by multiple variables ( that sometimes interact w/ one another)

-Can see how factors influence behavior
(1) Independently (main effect)
(2) Together (intercation effects)

Question 9

Mixed factorial designs

Answer 9

one factor is a between-subjects factor (e.g., alcohol), and one factor is a within-subjects factor (e.g., amount of caffeine).

Question 10

What are factors?

Answer 10

When two or more independent variables are combined in a single study

Question 11

What does a 2x3 factorial design represent?

Answer 11

A three factor design withtwo , three and two levels of each of teh factors respectively, for a total of 12 conditions

Question 12

How many independent variables are there in a 2x2x2 factorial design?

Answer 12

3

Question 13

How many separate groups of paticipants would be needed for a between subjects, two factor study wuth there levels of factors A and for levels of factor B?

Answer 13

12

Question 14

A researcher who is examining the effects of temperature and humidity in ther eating behvaior of rats uses a factorial experiment comparing three diffrent temperatures (70,80 and 90) and two humidity conditions (low and high) . How many factors are in the esperiment?

Answer 14

2 (low and high)

Question 15

How can a two factor design be presented

Answer 15

in a matrix in which the levels of one factor determine the column and the levels of teh second factor determinesthe rows

each cell in teh matrix contributes to to a certain combination of the factors that is a separte treatment condition

Question 16

What is teh diffrence between the two column called

Answer 16

main effect for the mode of presentation

Question 17

A mixed design

Answer 17

is a factorial study that combines two diffrent research designs. A common example of a mixed design is a factorial study with one between subjects factor and one within subjects factor

Question 18

A combined strategy

Answer 18

this study uses two differnt research strategies in the same factorial design.One factor is a true independent variable (experimental strategy ) and one factor is a quasi independant variable (non experimental strategy)

Question 19

Interaction between factors

Answer 19

Occurs when two factors acting togther, produce mean differences that are not explained by the main effects of rhe two factors. On the other hand if the main effect fo reither factor apllies equally across all levels of teh second factor, then the two factors are independent and there is no interaction

Question 20

A factorial study measures symptoms before and after taking medication for a group taking the medication and a control group taking placebo. What kind of design is being used?

Answer 20

mixed design

Question 21

The students in a gym class receive a self esteem program as part of their sports training. To evaluate the program, a researcher measures self esteem for the students before and after the program but was meaured at the same two times. What kind of design is being used ?

Answer 21

mixed design

Question 22

A researcher is interested in the effects of both caffeine consumption and exercise on cognitive performance. They design a study with two levels of caffeine consumption (no caffeine vs. moderate caffeine) and two levels of exercise (no exercise vs. 30 minutes of moderate-intensity exercise). Participants are randomly assigned to one of four groups:
●No caffeine, no exercise
●No caffeine, exercise
●Caffeine, no exercise
●Caffeine, exercise

Following their assigned condition, participants complete a cognitive task measuring reaction time.

1.What type of design is this study?
2.What are the factors in this study?
3.What are the possible main effects and interaction effects that could be observed?

Answer 22

1.This study is a 2x2 factorial design. This means that there are two factors, each with two levels, resulting in four total conditions.

2.The factors in this study are caffeine consumption and exercise.

3.Main effects:
Caffeine consumption: Participants who consume caffeine may have faster reaction times than participants who do not consume caffeine.

Exercise: Participants who exercise may have faster reaction times than participants who do not exercise.

Possible interaction effect:
The effect of caffeine consumption on reaction time may differ depending on whether participants exercised. For example, caffeine may have a larger positive effect on reaction time for participants who exercised than for participants who did not exercise.

Question 23

Explain the difference between probability sampling and nonprobability sampling, and provide one example of each.

Answer 23

Probability sampling methods are used when the exact size of the population is known, each individual’s probability of selection is known, and selection is truly random . One example is simple random sampling, where every member of the population has an equal chance of being selected .

Nonprobability sampling is used when it’s impossible to list every individual in the population, so the probability of selection is unknown. This approach is more common in behavioral sciences. An example is convenience sampling, where researchers select participants based on accessibility and convenience.

Question 24

A researcher believes that individuals who report higher levels of stress will also report poorer sleep quality. They administer questionnaires assessing stress and sleep quality to 100 participants. What type of research strategy is being used in this study?

Answer 24

This study uses a correlational research strategy. The researcher is examining the relationship between two continuous variables: stress levels and sleep quality, without manipulating either variable . They are simply measuring both variables to see if they co-vary . This approach seeks to describe the relationship between the variables but does not explain it or establish causality

Question 25

Main effects ?

Answer 25

independandnet influences if one factor on the DV

Examined by making mean comparisons among the rows and among the columns. One main effecrs for each factor in a design

i.e: Main effect Alcohol (factor A) examine the mean differences between rows.
Alcohol group had slower reaction times, so worse performance, relative to the no alcohol group, indicating a main effect of alcohol on reaction times.

Question 26

interaction effectsDetecting intertaion Visually

Answer 26

in a line graph an interaction is likely when the individual lines rep levels of one factor are not parallel

in a bar garph, and intercation is likely when teh pattern of bar heights within groups/levels are not the same

Question 27

How can order effects be measured and evaluated?

Answer 27

Use a factorial design adding a participant variable (such as age) as a second factor

Question 28

How can variance be reduced in a between subject design ?

Answer 28

Counterbalance and use a factorial design withthe order of treatments as a secodn factor