Chapters12-18

Question 1

Target population

Answer 1

Aggregate of all the individuals whose characteristics are the focus of the marketing research project

• target market
• sampling units

Question 2

Census

Answer 2

Act of measuring all the individuals in the pop.

• expensive
• time consuming
• technically demanding
• intrusive
• may miss individuals systematically–>bias

Question 3

Sample

Answer 3

Group of individuals drawn from a pop.

-smaller than target market

Question 4

Sampling frame

Answer 4

A procedure used to select the sample for the target pop

• a list of all the individuals in the pop
• a rule or set of directions to find all the individuals in the target market

Question 5

Bias

Answer 5

Systematic error: error-producing factor that is stable and operates in a constant direction
- cannot be quantified or identified

Question 6

Random error

Answer 6

Sampling error: a sample does not include all members, so it may underestimate or overestimate the true avg. measure of a characteristic in a pop.

Question 7

Simple random sample

-a probability sample

Answer 7

A probability sample; each sampling unit has the same chance of being sampled, and selection is based on a lottery model

• expensive due to sampling frame
• statistically inefficient

Question 8

Cluster sample

-probability sample

Answer 8

Population is divided into subsets, and process is repeated several times

• reduces sampling costs
• high sampling error due to less precision

Question 9

Stratified sample

-probability sample

Answer 9

The population is divided into segments, and each stratum is sampled separately

• increases high statistical efficiency
• more costly, the more strata, the higher the cost

Question 10

Convenience sample

-non-probability sample

Answer 10

Selection of sampled individuals is based on ease of access and convenience
-exploratory/used for pilot surveys

Question 11

Judgment sample

-non-probability sample

Answer 11

Selection of sampled individuals is done by interviewer based on some criterion
-exploratory/used for pilot surveys

Question 12

Quota sample

Non-probability sample

Answer 12

Selection of sampled individuals is based on the goal of including certain subgroups & the judgment of the interviewer

Question 13

Population parameters

Answer 13

The mean & standard deviation used to determine the distribution of a measure

Question 14

Sample mean

Answer 14

It is a variable & depends on the sample

• own distribution: range of possible values
• the pop. mean is the most likely value
• normal curve
• the standard error of the mean gives a measure of the variability of the sample mean
• standard error of the mean is inversely related to the sample

Question 15

What to consider when determining sample size?

Answer 15

• remain within budget constraints
• we want a precise sample statistic
• reliable sample statistic for inference about the population

Question 16

How do we determine sample size?

Answer 16

We rely on secondary information to learn about the population.
-variability of the target measure

Question 17

Confidence intervals approach

Answer 17

Population mean=sample mean +/- margin of error [m = X +/- (z)(sX)]

• Desired level of precision=margin of error
• Needed info: sd. in the pop.
• Statistical input: Z score corresponding to a certain confidence level eg. 95%:Z=1.96, 90%=1.64, 99%=2.58

Question 18

Size of the margin of error

Answer 18

• smaller margin of error- higher precision

- the level of confidence + the sd. error of the sample mean

Question 19

Standard error of the sample mean

Answer 19

Depends on the standard deviation of the measure in the pop. & the sample size

Question 20

Margin of error

Answer 20

(Z)(sX) = (Z)(S)/square root of n

-set the acceptable level of confidence, level of Z

Question 21

What makes a questionnaire defective?

Answer 21

• incomplete
• blank responses for most measures or key measures
• unsatisfactory or blank responses must be reported in project report

Question 22

What is the bottom line of the sample size?

Answer 22

1. large variability- high sd= large sample
2. precise estimate-smaller margin of error-larger sample
3. Precise estimate can be obtained by having lower confidence- greater uncertainty

Question 23

Statistical inference

Answer 23

The process of extrapolation: estimating beyond the original observation range the value of a variable through a hypothesis

Question 24

Hypothesis Ha

Answer 24

A discovery that you hope to establish

Question 25

H0- the status quo

Answer 25

The ignorance hypothesis

• implies that we get no new knowledge from this piece of research
• is never really accepted

Question 26

If research hypothesis Ha is true and the sample data is consistent with Ha=

Answer 26

Correct decision.

Probability: Power of the test (1-b)

Question 27

If research hypothesis Ha is true and the sample data is inconsistent with Ha=

Answer 27

Sample evidence leads to Type II error

Probability that this occurs: beta (b)

Question 28

If the research hypothesis Ha is false, and the sample data is inconsistent with Ha

Answer 28

=sample evidence leads to correct decision

Probability: Confidence level (1-a)

Question 29

Product-moment correlation coefficient (r)

Answer 29

Measures the strength of linear relationship bet. Two variables

• variables bet. -1 & 1
• > if r is close to 1, rel. is strong & pos.
• > if r is close to -1, rel. is strong & neg.
• > if r is close to 0, rel. is weak

Question 30

Simple regression

Answer 30

Assumes one variable affects the other but not vise versa (X–>Y)

Y=a+bX=e

Question 31

Multiple regression

Answer 31

Represents the rel. bet. A dependent variable Y and a set of independent variables (X1,X2,X3,…) with a linear function

Y=a+b1X1+b2X2+b3X3+…+e