The study uses a Randomized Block Design, where volunteers are grouped by income (blocks) and randomly assigned to advertising methods (treatments). The score on the recall exam is the key variable (response), while the type of advertising is manipulated (explanatory). There are four treatment levels (advertising types) and income level serves as the blocking variable. This design helps control for income's impact on recall and compare the effectiveness of different advertising methods within income groups.
Analysis of the Marketing Research Design:
a) What type of experimental design is this?
This is a Randomized Block Design.
- The volunteers are divided into blocks based on their income level, a blocking variable.
- Within each block, participants are randomly assigned to the different advertising groups.
b) What is the response variable in this experiment?
The response variable is the score on the recall exam. This is the variable being measured to assess the effectiveness of the different advertising methods.
c) What is the explanatory variable that is manipulated and set at various levels?
The explanatory variable is the type of advertising. This is the variable being manipulated by the researcher, with different levels representing print, radio, television, and online advertising.
d) How many levels of treatment are there?
There are four levels of treatment, corresponding to the four different types of advertising: print, radio, television, and online.
e) What variable serves as the block?
The variable serving as the block is the income level of the subjects. This is used to control for potential differences in recall ability due to income level.
f) Diagram of the Design:
The diagram given below shows the four blocks of income levels, each with four treatment levels (advertising types) randomly assigned to the volunteers within the block.
The probable question may be:
A marketing research firm wants to determine the most effective method of promoting a new book: print, radio, television, or online. They recruit 460 volunteers to participate in the study. The researcher segments the volunteers by level of income. Of the 460volunteers, 140 earn below $20,000, 140 earn between $ 20,000 and 40,000, 60 earn between $40,000 and $60,000 and 120 earn over $60,000 The volunteers from each group are randomly assigned to either the print advertising group, the radio group, the television group, or the online group. Each group is exposed to the advertising. After 3 hours a recall exam is given with the proportion of correct answers recorded. Complete parts (a) through (f) below.
a) What type of experimental design is this?
Completely randomized design, Randomized block design, Matched-pairs design, or Case-control study
b) What is the response variable in this experiment?
The income level of the subjects, The type of advertising, The time before the recall exam, or The score on the recall exam
c) What is the explanatory variable that is manipulated and set at various levels?
The score on the recall exam, The type of advertising, The income level of the subjects, or The time before the recall exam
d) How many levels of treatment are there? (Type a whole number.)
e) What variable serves as the block?
The type of advertising, The time before the recall exam, The income level of the subjects, or The scores on the recall exam
f) Draw a diagram to illustrate the design.