MKT 3340 Final exam review

What is the Procedure for Drawing a sample?

Step 1: Define the target population
- Target population: Section you are interested in studying.
Step 2: Identify the sampling frame.
Step 3: Select a sampling procedure.
Step 4: Determine the sample size.
Step 5: Select the sample elements.
Step 6: Coll

Define Target population

- Population is denoted by (N)
- Researchers must be very clear and precise in defining the target population.

What is a population?

The entire group under study as specified by the research project.

What is a parameter?

- A characteristic or measure of a population.

What is a statistic?

- A characteristic or measure of a sample!

What is a sample?

- A subset of a population, often taken to make inferences about the population. We calculate statistics from samples.

How are statistics calculated?

- Statistics are calculated from sample data and used to estimate population parameters.

Why are samples used?

When collecting primary data, market researchers rely on samples because:
- taking a census of everyone is time consuming.
- Very costly
- May lead to measurement errors
- Using a sample can generate results that generalize the entire population.

What is a census?

An accounting of everyone in the population.

What is a sampling error?

Any error in a survey that occurs because a sample is used.
- Usually caused by method of sample collection or sample size.

What is a sample frame?

A master list of all the members of the population.

What do commonly used sampling frames include?

- Custom databases
- Telephone directories
- Lists developed by data compliers

What is a sample frame error?

the degree to which the sample frame fails to account for all of the population due to misrepresentation, overrepresentation, and/or underrepresentation.

What are the 3 factors that affect the size of sample needed when working with a probability sample?

1. Amount of diversity or variation.
- As diversity/variation increases, larger samples are required.
2. Degree of precision
- As need for precision increases, larger samples are required.
3. Degree of confidence.
- Confidence increases as sample size inc

Determining the sample size:

- Size of the population has no bearing on the size of the sample.
- Desired variation, precision, and confidence drive the sample size.
- The more similar the population elements, the fewer people needed regardless of how large the population is.

Does the size of the population have any bearing on the size of the sample?

No

What is the Z value for the 95% confidence interval?

Z = 1.96

What is the Z value for a 99% confidence interval?

Z = 2.58

What are the 3 ways to estimate variance p times q?

1. Assume the most conservative case and use the maximum amount of variance we would expect in the population.
2. Use data from a previous study conducted on the same population.
3. Conduct a small pilot study to estimate variance.

What are the 2 major types of sampling plans?

Probability and non-probability sampling plans

What is a probability sampling method?

- A random sample is one in which every member of the population has an equal chance, or probability, of being selected into the sample.

What are the 4 probability sampling methods?

1. simple random sampling
2. systematic sampling
3. cluster sampling
4. stratified sampling

What random digit dialing? (RDD)

A method of randomly generating numbers to represent telephone numbers.
- This method is used in telephone surveys to overcome the problems of unlisted and new telephone numbers.

What is plus one dialing?

The number drawn from the directory has the last digit in the number replaced by a random number. This ensures that both listed and unlisted numbers are included in the sample.

What is cluster sampling?

In cluster sampling: the population is divided into subgroups, called "clusters."
- If each cluster is representative of the population, one or a few clusters can be selected and a census can be performed. This is a one-step area sample.

What is non-probability sampling?

Not every element of the population has an opportunity for selection to be used in the sample. This method is more commonly used in nursing studies.
- Because of this we cannot say that a sample drawn using a nonprobability sampling method is representati

Why are non-probability samples used?

- They are fast, simple to use, and less expensive than probability sampling methods.

There are 4 non probability sampling methods:

1. convenience samples
2. Judgemental samples
3. Referral samples
4. Quota samples

There are 5 types of errors:

1. Sampling error
2. Non coverage error
3. Non responsive error
4. Response error
5. Office error

What can non-sampling errors occur from?

Because of errors in:
- conception
- Logic
- Interpretation of questions and replies
- statistics/arithmetic
- analysis, coding or reporting

What is a non coverage error?

Due to failure to include some units, or entire sections, of the defined target population in the sampling frame.

What are non response errors?

- Refusals: designated respondents refuse to participate in the study.
- Not-at-homes: respondents are not at home when interviewer calls.
- Response errors: Response is inaccurate due to dishonesty, not comprehending, not willing, wording making it bias.

How is the general response rate calculated?

RR = CI/E
RR: response rate
CI: Completed interviews
E: Number of eligible responding units in the sample

What is selection of field workers?

- Develop job specifications for the project, taking into account the mode of data collection.
- Decide what characteristics field workers should have.
- Recruit appropriate individuals.

What are general qualifications for field workers?

- Health
- Outgoing
- Communicative
- Pleasant appearance
- Educated
- Experienced

What is the evaluation of field workers?

- Cost and time
- Response Rates
- Quality of interviewing
- Quality of data

What is considered in a frequency distribution?

One variable is considered at a time

What is the mean?

It's the average value and it's the most commonly used measure of central tendency.

What is the median?

The middle value when the data are arranged in order. You add the 2 middle values and divide by 2.

What is the mode?

value that occurs most often.

What is the range?

the difference between the highest and lowest scores in a distribution

What is skewness?

The tendency of the deviations from the mean being larger in one direction than in the other.

What is a null hypothesis?

One of no difference or no effect. If the null hypothesis is not rejected, no changes will be made.

What is an alternate hypothesis?

Some difference or effect is expected.

What is the t-statistic?

It measures how close the sample has come to the null hypothesis.

When are t-tests used?

Small sample, n < 30

When are Z-tests Useful?

When there is a large sample, over 30 n > 30

What is the procedure for hypothesis testing?

Step 1: Formulate the hypothesis
Step 2: Select an appropriate test
Step 3: Choose a level of significance
Step 4: Collect data and calculate test statistic
Step 5: Determine the probability
Step 6&7: compare the probability (critical value) and making th

What is a type 1 error?

It occurs when the sample results lead to the rejection of the null hypothesis when it is in fact true.
- The probability of type I error (?) is also called the level of significance.
- Typically a value of 0.05 is selected for ?

What is a type 2 error?

Based on the sample results, the null hypothesis is not rejected when it is in fact false.
- The probability of type II error is denoted by ?.

What is univariate analysis?

the analysis of a single variable, for purposes of description.

What is multivariate analysis?

An analysis involving Multiple variables!

What are nominal and ordinal measures referred as?

Categorical measures

What are interval and ratio measures referred as?

Continuous measures

What are descriptive statistics for metric data?

Statistics that describe the distribution of responses on a variable.
- The most commonly used descriptive statistics are:
the mean and the standard deviation

Percentages?

are very useful for interpreting the results of categorical analyses and should be included whenever possible

What is generalization?

The act of estimating a population fact from a sample finding.

What are 2 types of evidence?

1. Variability: less is more
2. Sample Size: More is more

Why Conduct Multivariate Analysis?

Multivariate analyses allow researchers a closer look at their data than is possible with univariate analyses.

What is cross tabulation?

A multivariate technique used for studying the relationship between two or more categorical variables.

What is analysis of variance (ANOVA) used for?

It is used as a test of means for 2 or more populations.

What is a treatment?

A particular combination of factor levels, or categories.

What is a one way analysis of variance?

Involves only one categorical variable, or a single factor. In one-way analysis of variance, a treatment is the same as a factor level.

What is n-way analysis of variance?

If two or more factors are involved.

What is the product moment correlation? (r)

It summarizes the strength of association between two metric (interval or ratio scaled) variables, say X and Y.

what is the dependent variable?

The dependent variable is the one that is predicted, and it is customarily termed y in the regression straight-line equation.

What is the independent variable?

The one that is used to predict the dependent variable, and it is the x in the regression formula.

What does multiple regression tell us?

- which factors predict the dependent variable
- which way (the sign) each factor influences the dependent variable, and
- how much (the size of bi) each factor influences it

What does the front section of a marketing research report include?

� Title page
� Letter of authorization/approval of research proposal � Table of contents
� List of illustrations
� Executive summary