1. MARKETING RESEARCH CHAPTERS
7: Descriptive Research Design: Survey and Observation
8 Experimentation

2. Descriptive Research Design: Survey
The survey method is a structured questionnaire given to a sample of a population designed to elicit specific information from respondents.
The survey has the following advantages: ease, reliability, and simplicity (the ease of removing the information from the structured questionnaire and putting the information into computerized form).
The survey has the following disadvantages: respondents may be unable or unwilling to provide the information and it may be difficult to get a sampling frame to draw a representative sample.

3. Descriptive Research Design: Survey: Modes
Telephone: Traditional and computer-assisted telephone interviewing
Personal: in home, mall intercept, computer assisted personal interviewing
Mail: mail panel, mail/fax interview
Electronic: or internet

4. Advantages and Disadvantages of Telephone Interviewing
Interviews completed quickly
No travel time
Limited labor costs
Sample control high
Supervision from central location
Response rate good
Personal rapport difficult to achieve
Respondents can escape easily
Less tolerance for lengthy interviews

5. Advantages and Disadvantages of Personal Interviews
In-home:
Provides clarification to respondent
Can use visual aids
Easy to sample homes
Respondents tolerate longer interviews
Response rate good
However people home now so difficult to
find respondent at home
Interviewer control difficult
More social desirability problems
Interviewers can influence answers-interviewer bias

6. Advantages and Disadvantages of Personal Interviews
Mall Intercept:
Respondent is already present in mall
Research facilities in many malls
Appropriate when there is a need to
handle product
Response rate good
Social desirability issues
Interviewer bias
Limited data can be collected as people are in
a hurry
High cost

7. Advantages and Disadvantages of Personal Interviews
Computer Assisted Personal Interview
Holds respondents interest
Can ask completed set of questions
as computer automatically carries
out skip pattern
Computer administers interview
Interviewer bias limited
Useful when physical stimuli needed
Good control of data collection
Good response rate
Social desirability issues
Limited data
High cost

8. Advantages and Disadvantages of Mail Methods
Economical
Can reach lots of people
No personal contact so no interviewer bias
Moderate to large amounts of data
People can easily throw away the survey
Low sample control
Response rates very low
Can result in non-response bias

9. Improving Survey Response Rates
Prior notification
Incentives (monetary and non-monetary)
Follow-up
Other facilitators of response such as reminders

10. Observation Methods
Personal observation
Mechanical observation

11. Advantages and Disadvantages of Observation
Do not require conscious respondent input
Interviewer bias control since observer only puts down what is observed
Easier to use with pets and children
Best applied to phenomenon that occur frequently or are of short duration
We do not know why something is happening – subject to subjective analysis
Not good for infrequent behavior or behavior of long duration (although anthropologists have used this method effectively living with people for long periods of time)

12. Causal Research Design: Experimentation
What is the meaning of causality?
Causality: when the occurrence of variable X increases the probability of the occurrence of Y
To have causality: if the two events occur together one might cause the other, but one must actually precede the other, and there must be no other event that could cause the second event

13. Experimentation
To actually show cause and effect, we must set up an experiment.
An experiment is the process of manipulating one or more independent variables and measuring their effect on one or more dependent variables while controlling for extraneous variables.
An independent variable is the cause of something and usually manipulated by the researcher
The dependent variable is the effect of changes in the independent variable
Experiments use test units: anything sampled or selected for an experiment.

14. Experimentation Continued
We control for extraneous variables or other things than the independent variable that might affect the response of test units.
The most usual way of controlling for extraneous variables is to use random assignment of test units to the experimental groups.
There are often two types of groups in an experiment: control and experimental groups.
The control group is the comparison group and the experimental group you will change in some way. You will then compare results between the two groups.
Normally, you will DESIGN your experiments

15. Experimental Design
We can use specific symbols help organize how we think about experimental design:
X = The exposure of a group to some kind of change often called a treatment
O= The process of observation or measurement of the dependent variable on the test units.
R= The random assignment of test units to separate treatments or groups.

16. Experimental Design Continued
Designs can be pre-experimental, true experimental, quasi-experimental, and what your book calls statistical designs although with the other designs it is possible to use statistics as well.
Pre-experimental designs do not use randomization.
One shot case study: X O1
One-group pretest-posttest: O1 X O2
Static Group Design: EG: X O1
CG O2

17. Experimental Design Continued
True experimental designs use randomization which is one method for controlling for extraneous variables.
Randomization means that you know the probability of selecting each test unit for a particular group.

18. Experimental Design Continued
Pretest-posttest control group design:
EG: R O1 X O2
CG: R O O4
The treatment effect is measured as the difference: (O2-O1)-(O4-O3).
There may be a problem with this design although it is very common: interactive testing effects
Posttest-Only control group design:
EG: R X O1
CG: R O2
The treatment effect is: O1-O2

19. Validity in Experimentation
Internal validity refers to whether the manipulation of the independent variables or treatments actually caused the observed effects on the dependent variables. Control of extraneous variables is a necessary condition for establishing internal validity.
External validity refers to whether the cause-and-effect relationships found in the experiment can be generalized. To what populations, settings, times, independent variables, and dependent variables can the results be projected?

20. Extraneous Variables
History refers to specific events that are external to the experiment but occur at the same time as the experiment.
Maturation (MA) refers to changes in the test units themselves that occur with the passage of time.
Testing effects are caused by the process of experimentation. Typically, these are the effects on the experiment of taking a measure on the dependent variable before and after the presentation of the treatment.

21. Extraneous Variables
Instrumentation (I) refers to changes in the measuring instrument, in the observers, or in the scores themselves.
Statistical regression effects (SR) occur when test units with extreme scores move closer to the average score during the course of the experiment.
Selection bias (SB) refers to the improper assignment of test units to treatment conditions.
Mortality (MO) refers to the loss of test units while the experiment is in progress.

22. Experimental Design Continued
Quasi-experimental designs include time series designs where you look at changes in a variable over time.

23. Experimental Design Continued
Statistical designs consists of a series of basic experiments that allow for statistical control and analysis of external variables.
They offer advantages in that the effects of more than one independent variable can be measured, extraneous variables can be controlled, and designs can be used where each subject is measured more than once.
Generally, these designs are called Analysis of Variance Designs. One type of this design is called factorial which we will discuss when we look at ANOVA (analysis of variance designs).