KIN 232 Module 4

Question 1

Experimental designs

Answer 1

Specifically testing hypotheses in a systemic manner

Deliberate consideration of variables

A major aim is to examine a cause and effect relationship

1. Manipulation of variables (independent variables)
2. Control group
3. Random assignment

Question 2

Experimental research

Answer 2

Participants are assigned to an interventional group

Researcher manipulates the level of the independent variable by group

Question 3

Types of independent variables

Answer 3

Active variable: an independent variable that can be manipulated (ex drug dosage)

(Experimental research must have at least one active variable)

Attribute variable: an independent variable that cannot be manipulated (genetics, geography)

Question 4

Control groups

Answer 4

The group you compare your intervention group to

Shares many characteristics as experimental/intervention as possible except the actual intervention

Group equivalents

Question 5

Random assignment

Answer 5

every participant has the same chance of being assigned to any group in the study

Guarantee traits balance out in an infinite population but not in a finite sample

Assumption that there is balance

Question 6

Blocking and Random

Answer 6

Step 1: Randomization– randomizing within blocks of a trait (sex, age)

Step 2: Blocking – separating people based on attribute variable (not random)

Step 3: Randomly assigned people from each block into control or intervention group (randomization)

Question 7

Matching

Answer 7

Not randomization
match on key variables and then assign them to opposite groups

Not for experimental

Bias associated with it

Question 8

Limitations to experimental

Answer 8

• MUST manipulate variables
• Controlling many variables causes a poor external validity
• expensive/difficult to manipulate intervention

Question 9

Masking

Answer 9

Individuals involved in the experiment are prevented from knowing certain information about the study

Ex. Intervention or group they belonged into

Typically masking the participant

Question 10

Masking participants

Answer 10

Expectation that experimental group will influence behavior

Question 11

Masking researchers administering intervention

Answer 11

Could change how researcher administers intervention

Question 12

Masking of Researchers Evaluating Outcome

Answer 12

Experimental group will have better (or worse) may influence measurement, especially where not entirely objective

Question 13

Placebo

Answer 13

A dummy treatment administered to the control group to distinguish specific and nonspecific effects of the experimental treatment

Participants are generally masked to group assignment by administration of a “placebo condition”

Question 14

The placebo effect

Answer 14

observable, tangible, measurable effects, nothing to do with the intervention

effects in cases of pain, depression, insomnia, anxiety

Question 15

Number of assessments: Randomized control trial

Answer 15

(most common way to determine cause and effect in experimental design)

Pre test and post test

Question 16

Number of assessments: Post only disadvantages

Answer 16

Disadvantage: doesn’t ensure the group are all the same at the beginning (group equivalents) , only relying on random assignment since we are missing pre test

Question 17

Number of assessments: Repeated measures

Answer 17

A midpoint observation during intervention

To determine when the intervention will have its effect (temporal aspect)

A washout period after post-test where they stop administering the intervention

How long does it take for the intervention to linger after administering

Question 18

Number of Experimental groups: Different levels of groups/independent variables

Answer 18

An additive effect that will improve dependent variable (0 mg to 100 mg to 200 mg – dose effect)

Dose response relationship (dose value linearly or non-linearly related to independent variable)

To determine what dose is the most effective

Question 19

Number of Experimental groups: Repeated measures between subject (between subjects design)

Answer 19

Participants are assigned to and only receive 1 level of the independent variable

Examines the variability and differences BETWEEN groups

“What is the effect of each intervention”

Question 20

Number of Experimental groups: Repeated measures within subject design (within subject design)

Answer 20

Participants receive every level of the independent variable

Examines the variability and differences within a person, and of course examines the effect of the independent variable

The different levels of the independent variable can be given to the participants in a randomized or fixed order

You act as your own control and compare outcomes to your results

Question 21

Number of Experimental groups: Crossover design

Answer 21

Allows for washout period in between interventions

Reduces the likelihood of carryover effects

Preferred when only two interventions are used

Question 22

Having more than 1 independent variable allows for

Answer 22

creation of a factorial design (multifactoral)

Question 23

Number of independent variables..

Answer 23

2 independent variables referred to as 2 way design
3 variables refers to 3 way design

Question 24

2 independent variables with 2 levels of each

Answer 24

2x2 factorial design

Question 25

2 independent variables, one independent variable with 2 levels and the other independent variable with 3 levels

Answer 25

2x3 factorial design

Question 26

3 independent variables with 2 levels of each

Answer 26

2x2x2 factorial design