behave research methods quiz # 5

Why can't participants in a quasi experimental variable be randomly assigned?

1) Nature assigns participants to level Ex: Gender, skin color, age, etc. 2) Unethical to randomly assign participants to different levels of IV Ex: Abused, breast fed, circumcised 3) Participants pre-assigned to conditions Ex: Students assigned to different classes through means other than random assignment

What are the two reasons more than 1 IV is studied

1) human behavior is complex 2) in any give situation there is likely more than 1 variable affecting behavior/mental processes

How many conditions does a 2x3x2 design have

12 conditions

2x4 factorial design

2 Ivs IV1 has 2 levels IV2 has 4 levels

What is the simplest factorial design

2x2 factorial design Each number represents an IV in study Two IVs (factors) Each numeric value represents the # of levels for each IV Each IV has two levels

2x2x2 equals

3IVS IV1 has 2 levels IV2 has 2 levels IV3 has 2 levels 8 conditions

3x2x4 factorial design

3IVs IV1 has 3 levels IV2 has 2 levels IV3 has 4 levels

How many conditions does a 2x2 design have

4 conditions (cells)

In a factorial design, how can participants be assigned to conditions?

Between-subjects Within-subjects Mixed

Quasi-experimental variables

DO NOT allow for causal conclusions and Cannot/haven't randomly assigned participants to different levels

Do the effects of height on dunking depend on BMI? What is the DV? What is IV1? What is IV 2?

DV = dunking IV1 = height IV2= BMI

Do the effects of height on dunking depend on BMI? What is the interaction?

Do the effects of height on dunking depend on BMI?

Interactions

Does the effect of one variable on the DV depend on the level of the other IV(s)?

IV =

Factor

Quasi experimental variables have

Lower level of control Participants cannot be/haven't been randomly assigned to different levels of IV

Describe an experimental design for a one Independent Variables in study

One-way (caffeine consumption (present vs. absent) between-subjects design with word recall as DV. A one-way can ONLY be between or within

A researcher was interested in the effects of music type (rock, classical, jazz) and age (child, young adult, senior) on mood. Therefore, she randomly assigned each participant to either the rock, classical, or jazz conditions. After going through the assigned conditions, she had each participant rate their mood on a 10-pt mood scale. Based on this description, this study utilizes a __________ .

Quasi-experimental design

Do the effects of height on dunking depend on BMI? What is 1 potential main effect?

Regardless of/ averaging over BMI (IV2) does height(IV1) affect dunking(DV)?

Do the effects of height on dunking depend on BMI? What is the 2nd potential main effect?

Regardless of/ averaging over height (IV1) does BMI(IV2) affect dunking(DV)

Do the effects of caffeine on memory depend of gender. What is the main effect of gender?

Regardless of/ averaging over levels of caffeine intake, does gender affect memory (number of words recalled)?

Do the effects of caffeine on memory depend of gender. What is the main effect of caffeine consumption?

Regardless of/averaged over levels of gender, does caffeine consumption affect memory (number of words recalled)?

Do quasi experimental variables allow us to draw causal conclusions?

They NEVER allow us to draw causal conclusions

Who assigns participants to the IV conditions in a quasi experiment

They are assigned to the IV conditions by teachers, political regulations, acts of nature or by their own choice

Describe an experimental design for three Independent Variables in study

Three-way (caffeine consumption (present vs. absent) x time of day (morning vs. night x room temperature (50 vs. 72 vs. 90 degrees) between-subjects design with word recall as DV

Describe an experimental design for two Independent Variables in study

Two-way (caffeine consumption (present vs. absent) x 2 time of day (morning vs. night) between-subjects design with word recall as DV

Can factorial designs be between, within, or mixed

Yes

Do quasi experiments allow us to draw causal conclusions?

Yes, you can draw causal conclusions

An independent groups factorial design is also known as

a between subjects factorial

Factorial design

a design in which there are two or more independent variables aka factors. All levels of each IV are combined with all levels of other Ivs

an IV is also know as

a factor

Participants were asked to read a poem that was written by a male or female (gender) author who they were told was either an English major, college student, or an English professor (level of expertise). Regardless of the gender of the author, the participants rated the poem written by the professor as being of higher quality than the poem written by the student. These results provide support for:

a main effect of level of expertise.

What design is most commonly seen?

a mixed subjects or factorial design

nonequivalent control group

a quasi experimental study that has at least one treatment group and one comparison group, but participants have not been randomly assigned to the two groups

Moderating variable

a variable that influences the relationship between two other variables

Professor Love was interested in determining if the effects of room color (white or black) on mood depended on room temperature (72 or 92). Therefore, she randomly assigned participants to one of four conditions: white room at 72 degrees, white room at 92 degrees, black room at 72 degrees, or black room at 92 degrees. In other words, participants were randomly assigned to either a white or black room and were randomly assigned to either a 72 or 92 degree room. After being in their assigned conditions for 2 hours, Professor Love had the participants rate their moods on a 10-pt scale. This study involves a ________ factorial design.

between-subjects

Within-groups aka repeated-measures factorial

both independent variables are manipulated as within-groups. Therefore, id the design is a 2x2 there is only one group of participants but they participate in all four combinations or cells of the design

Independent-groups aka between-subjects factorial

both independent variables are studied as independent groups. Therefore if the design is a 2x2, there are four different groups of participants in the experiment

Main effects

is the effect averaged over levels of the other IV or IVS and each factor has a main effect that needs to be looked at.

Mixed factorial design

one independent variable is manipulated as independent-groups and the other is manipulated as within-groups

Interactions ALWAYS

override main effects

How many levels does a participant go through in a within subjects design?

participants go through all levels of factor(s)

How many levels does a participant go through in a Between subjects design?

participants go through only 1 level of factor(s)

A within groups factorial design is also known as

repeated measures factorial

Professor Smith wanted to investigate whether the effects of sunlight (present vs absent) on mood depend on temperature (50 degrees vs 72 degrees). Therefore, in some order, each participant was exposed to sunlight at 50 degrees, sunlight at 72 degrees, darkness at 50 degrees, and darkness at 72 degrees. After each condition, participants were asked to rate their moods. This study involves a ________ factorial design.

within-subjects

Can quasi experiments be repeated measures design

yes, however the researcher takes advantage of an already scheduled event, a new policy or regulation or a chance occurrence to manipulate the IV