Research Design

Question 1

Explain the difference between experimental and non experimental design

Answer 1

Experimental (descriptive, correlational): They are meant to answer questions about causality, the researcher manipulates the variables (treatments) to establish causality (does smoking cause lung cancer?). There are the strongest protection against mistakes.

Non-experimental (experimental, quasiexperimental): They are meant to answer questions that have to do with describing things (what are the characteristics of smokers?) or how characteristics are related (is smoking related to lung cancer?). The researcher does not actively intervene.

Question 2

An RCT consists of how many levels with one Independent variable what do levels refer to

Answer 2

Consists at least two levels, including:
A treatment group
Some form of comparison or control group
Randomized: Refers to random allocation of participants to

Level is the amount of things the independent variable is comparing like the degrees and test taking situations like you are comparing a 90 degree room to a 50 degree room and seeing which one is better. so it has two levels.

Question 3

Issues with RCT’s

Answer 3

Is it true random sample???
Since all members of the defined population are available and willing to participate the study.

Some clinical issues…
Clinical procedures are effective or not??? They will work for whom???
RCT’s cannot tell which participants in a sample improved because of treatment and which ones improved because of extraneous factors

Question 4

Why is randomization good???

Answer 4

Random assignment in experiments is important because:
it helps to control confounding variables.
it ensures that the measures used are valid
it eliminates the problem of dependent variables.
it ensures that the measures used are reliable

Question 5

Factorial designs and the different levels

think of the room temperature example

Answer 5

Refers to the number of treatments (factors, IV)
One-Way (Single-factor) design: There is only one treatment (factor). It can have more than one level (different dosages, different durations, ..).
Two-way factorial design: Examines two treatments and their interactions.
Three-way factorial design: Examines three treatments and their interactions

Question 6

what is a single factorial (think only one group with a pre test and post test)

Answer 6

Pretest-posttest control-group design
Posttest-only control group design
Single-group pretest-posttest design
Nonequivalent control group design
Time series design
Repeated measures or repeated treatment designs

Question 7

Pretest-posttest control-group design what is this

Answer 7

Think of a placebo group added to a RCt

so you Have treatment group 1 pre o x o post

group 2 o pre D o post and D is the sham or placeboo

group 3 o o o is for a coventional control group

Question 8

Post-test only

Answer 8

Test group 1 R X O

test group 2 R O

Question 9

Single group pre and post test design not an RCT or

Answer 9

test group 1 O X O O = testing

X=intervention

Question 10

Nonequivalent control-group design explain

Answer 10

When a nonrandom control group is available.
It is not RCT but between-groups design

Group 1: O X O
Group 2: O O

Question 11

Time-Series Design

and advantages

Answer 11

It is used to establish a baseline of measurements before initiation of treatment to either a group or an individual.
If it is important to assess changes over many time intervals

: Group 1: O O O O O X O O O O

to study the effect of something over time

They are widely used in health science research.
Repeated measures for different treatments
Any pretest-posttest designs
Within-subject or within-groups designs
Randomized

Question 12

explain carry over effect or order effect

think medication wise and how do you eliminate this???

Answer 12

If there are more than two treatments or more than two levels of and independent variable
Order effect: the order in which they are presented may influence the outcome.
Carryover effect: a treatment can enhance or diminish other treatment’s effectiveness
RANDOMIZATION minimizes these effects

Question 13

Multiple-factor experimental design explain

Answer 13

Researchers interested in:
The individual effects of the multiple factors on the dependent variable
The effects of the interaction between the multiple factors on the dependent variable

Question 14

explain a 2x2 2x3 3x3

Answer 14

2 x 2 2= groups being used and the 3 represents the number of factors being studied like temp of a 90, 50, room on group 1 and group 2

2X3 same deal just with another degree room like 30 degrees

3x3 3 = another group the first number is the number of groups and third number is the number of factors being tested that affect the dependent variable

Question 15

explain between groups and within-subject design

then group compared to other individuals

Answer 15

Between-subject design: Each subject is assigned to one group and only receives treatment given to that group. There are separate groups, and comparison is made between groups.

Within-subject design (repeated measures): Each subjects receives all treatments and outcomes for each subject are compared across these treatments

Question 16

Single-subject (case) design vs case studies or case reports

Answer 16

CASE STUDY: It is a description, very often a retrospective, of a curse of treatment of an individual. It is non-experimental.

SINGLE-SUBJECT DESIGN: There is controlled manipulation of an independent variable and are conducted prospectively.
Data from each research participant are analyzed separately. Single-subjects refers to the data rather than the number of participants.

Question 17

Characteristics of a Case study.

Advantages and Disadvantages

Answer 17

Skill acquisition and learning can be studied.
Treatment effect can be disassociate from recovery rate.
Individual response rather than average group response to the treatment can be studied.
Investigator know immediately rather than after statistical analysis whether performance is affected by treatment.
The design conforms to a clinical setting.
There is no need to withhold treatment in multiple baseline designs.

Disadvantages The problem of generalizing findings from one subject to a large population
A controversial issue is whether statistical analysis should be used.

Question 18

A-B design describe

Answer 18

In general, multiple measures are taken until an established baseline trend is established.
The investigator then administers treatment.

Phase A: No change in performance is expected without treatment.
Phase B: A change is expected with treatment

IN REHAB RESEARCH:
The initial patient examination is analogous to the A phase. However single-subject design requires a minimum of three data points in any phase.

Question 19

A-B-A or A-B-A-B designs

Answer 19

Are characterized by at least one implementation and withdrawal of treatment over the course of the study.
It answers the important clinical question, “Does this treatment work?”
There is ethical issue if the treatment is effective.
A: baseline phase
B: treatment phase
A: another baseline

Question 20

Multiple Baseline Design

Answer 20

Several subjects or behaviors are studied at the same time.
It answers whether or not a treatment is effective.
No ethical dilemma of withholding an effective treatment.

Question 21

A-B-C design

Answer 21

Include the use of different treatments, each administered independently of the other, within the same phase.

Answer the clinical question “which of two (or more) treatments is better?”

The treatments are rapidly alternated based on a random pattern.

It is well suited to treatments that are expected to have short-lived effects.
It is difficult to determine how “B” or “C” interacted or what effects both “B” and “C” had separately on the patient, therapist or department.