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o Internal Validity

A characteristic of an experiment in which data are collected in such a wat as to eliminate the effects of variables within the experimental environment that are not of interest to the researcher

o External Validity

A characteristic of an experiment whose results can be generalized beyond the test environment so that the outcomes can be replicated when the experiment is repeated

o Cluster Sampling

A method by which the population is divided into groups, or clusters, that are each intended to be mini-populations. A simple random sample of N clusters is selected. The items chosen from a cluster can be selected using any probability sampling technique

o Simple random sampling

A method of selecting items from a population such that every possible sample of a specified size has an equal chance of being selected

o Convenience Sampling

A sampling technique that selects the items from the population based on accessibility and ease of selection

o Time-Series Data

A set of consecutive data values observed at successive points in time

o Cross- Sectional Data

A set of data values observed at a fixed point in time

o Stratified random sampling

A statistical sampling method in which the population is divided into subgroups called strata so that each population item belongs to only one straturn. The objectives is to form strata such that the population values of interest within each straturn are as much possible. Sample items are selected from each stratum using the simple random sampling method.

o Systematic random sampling

A statistical sampling technique that involves selecting every Nth item in the population after a randomly selected starting point between 1 and N. The value of N is determined as the ratio of the population size over the desired sample size

o Ordinal Data

Allows decision makers to equate two or more observations or to rank-order the observations

o Statistical Sampling

Allows every item in the population to have a known or calculable chance of being included in the sample

o Interval Data

Allows us to precisely measure the difference between any two values

o Census

An enumeration of the entire set of measurements taken from the whole population

o Interview bias

Bias- an effect that alters a statistical result by systematically distorting it; different from a random error, which may distort on any one occasion but balances out on the average

• Which sampling method would most likely be used in an interview conducted with school principles of a sample of cities in California?

Cluster Sampling

• Which sampling method would most likely be used in a survey of people entering a fairgrounds in Springfield?

Convenience Sampling

o Qualitative Data

Data Whose measurements scale is inherently categorical

o Ratio data

Data that have all the characteristics of interval data but also have a true zero point

o Selection Bias

Do they share the same views, income, education levels, and so on

o Nominal Data

Lowest form of data, assigning codes to categories

o Quantitative Data

Measurements whose values are inherently numerical

o Observer Bias

People tend to view the same event or item differently

• Which sampling method would most likely be used in a poll of voters regarding a referendum calling for a national value added tax?

Stratified Random Sampling

o Nonstatistical sampling techniques

Those methods of selecting samples using convenience, judgment, or other nonchance processes

o Statistical sampling techniques

Those sampling methods that use selection techniques based on chance selection

o Nonresponse Bias

Those who respond may provide data that are quite different from the data that would be supplied by those who choose not to respond

o Measurement Error

Use of different measurement tools

o Data Accuracy

You need to check out the source to make sure that the data was collected and recorded properly

• A company has 15,000 employees. The file containing the names is ordered by employee number from 1 to 15,000. If a sample of 100 employees is to be selected from the 15,000 using systematic random sampling, within what range of employee numbers will the first employee selected come from?

o 1-150

• What is meant by a leading question?

o A leading question is worded in a way that will influence the response of the question.

• Experimental Design

o A plan for performing an experiment in which the variable of interest is defined. One or more factors are identified to be manipulated, changed, or observed so that the impact (or influence) on the variable of interest can be measured or observed

• Experiment

o A process that produces a single outcome whose result cannot be predicted with certainty

• ___ is used whenever the data have already been changed

o Bar chart

• Personal Interviews

o Can be structured or unstructured depending on the objectives and they can utilize either open-end or closed-end questions

• Two primary categories of statistical inference procedures

o Estimation o Hypothesis Testing

• Most useful and frequently used data collection methods

o Experiments o Telephone surveys o Written questionnaires and surveys o Direct observation and personal interviews

• Business statistics can be separated into two categories

o First category o Second category

• Assume you have received a class assignment to determine the attitude of students in your school toward the school's registration process. What are the validity issues you should be concerned with?

o For results to have external validity, the results of an experiment must be able to be replicated for groups different from the original sample o For results to have internal validity, any possible extraneous factors in the experiment must be controlled.

• _____ is used to display data over a range of values for the factor under consideration

o Histogram

• Structured interview

o Interviews in which the questions are scripted

• Unstructured interview

o Interviews that begin with one or more broadly stated questions, with further questions being based on the responses

• Determine the classification for the position variable

o Nominal

• Determine the classification for the size variable.

o Ordinal

• Direct Observation

o Procedure that is often used to collect data, requires the process from which the data are being collected to be physically observed and the data recorded based on what takes place in the process

• First category

o Procedures and techniques designed to describe data such as o Charts o Graphs o Numerical measures

• Demographic Questions

o Questions relating to the respondents characteristics, backgrounds, and attributes

• Open-End Questions

o Questions that allow respondents the freedom to respond with any value, words, or statements of their own choosing

• Closed-End Questions

o Questions that require the respondent to select from a short list of defined choices

• Determine the classification for the age variable

o Ratio

• Hypothesis testing

o Take a sample demographic and give them a test such as a blind taste test

• Suppose a large magazine would like to determine the average age and income of its subscribers. How could statistics be of use in determining these values?

o The magazine could use statisticalinference, particularly estimation, to determine these values by looking at a subset of the data

• Second Category

o Tools and techniques that help decision makers draw inferences from a set of data

• Estimation

o Used in situations in which we would like to know about all the data in a large data set but it is impractical to work with all the data

• Business Statistics

o a collection of procedures and techniques that are used to convert data into meaningful information in a business environment

• Statistical Inference Procedures

o procedures that allow a decision maker to reach a conclusion about a set of data based on a subset of that data

• Data Mining

o the application of statistical techniques and algorithms to the analysis of large data sets

• Business intelligence

o the application of tools and techniques for gathering storing retrieving, and analyzing data that businesses collect and use

• Arithmetic Mean or Average

o the sum of all values divided by the number of values