Standard deviation

As a measure of dispersion in statistics, this term indicates the extent of data spread-out. It is calculated by the square root of the variance. Units of the data researched and the standard deviation should be identical but percentage measuremetns should take percentage points expression.

t statistic

A statistic that assumes that the variable has a symmetric bell shaped distribution and the mean is known (or assumed to be known) and the population variance is estimated from the sample.

Standard error of estimate

One of the statistics associated with bivariate regression analysis. This statistic, SEE is the standard deviation of the actual Y values from the predicted (Y cap) values.

Sum of squared errors

One of the statistics associated with regression analysis. It refers to the distances of all the points from the regression line are squared and added together to arrive at the sum of squared errors, which is a measure of total error.

Substitute a neutral value

One of the options or methods available to a researcher in treating the missing responses from the filled up questionnaires. In this option, a neutral value, typically the mean response to the variable is substituted for the missing responses. Thus the mean of the variable remains unchanged and other statistics, such as correlations, are not affected much. Although this approach has some merit, the logic of substituting a mean value for respondents

Structure correlations

It is one of the statistics associated with the discriminant analysis procedure conducted for a marketing research project. Also referred to as discriminant loadings, the structure correlations represent the simple correlations between the predictors and the discriminant function.

Statistical control

In the context of conducting experimental research in marketing this refers to one of the methods of controlling extraneous variables by measuring the extraneous variables and adjusting for their effects through statistical analysis.

Standard error of the mean or standard error

The standard deviation of a sampling distribution of the mean. It is equal to the population standard deviation divided by the square root of the sample size. In the context of correlation and regression it is the standard deviation of b, variable i.e., SEb.

Statistical estimation

Involves the estimation of a population value we do not know from a sample value we do know. There are two kinds of estimation procedure, point estimation and interval estimation. Point estimate is a single number, or point, that is used to estimate a population value of interest. An interval estimate consists of two points between which the population value is estimated to lie with some stated level of confidence.

Test-retest reliability

An approach for assessing reliability in which repeating the measurement using the same instrument under as nearly equivalent conditions as possible to compare the similarity of responses. The degree of similarity between the two measurements is determined by computing correlation coefficient. The higher the correlation coefficient, the greater the reliability of the testing instrument

Dendogram (tree graph)

One of the statistics associated with cluster analysis technique used in marketing in general and marketing research in particular. This is a graphical device for displaying clustering results. Vertical lines represent clusters that are joined together. The position of the line on the scale indicates the distances at which clusters were joined. The dendogram is read from left to right.

Mean square

One of the statistics associated with one-way analysis of variance (ANOVA). The mean square is the sum of squares divided by the appropriate degrees of freedom.

Statistical (experimental research) designs

These are the more advanced experimental research designs than the basic and true
experimental designs. Statistical designs consist of a series of basic experiments that allow for statistical control and analysis of external variables. In other words, several basic experiments are conducted simultaneously. Statistical designs offer many advantages.

These are:
(1) The effect of more than one independent variable can be measures on dependent variable, (2) Specific extraneous variable can be statistically controlled, and (3) Economic designs can be formulated when each test unit is measured more than once.

Type II error

An error occurs, based on sample results, by accepting the null hypothesis when the alternate hypothesis is true. Also known as beta error. The probability of type II error is called the power of a statistical test.

Coordinates

One of the statistics and terms associated with multidimensional scaling procedures. Coordinates indicate the positioning of a brand or stimulus in a spatial map.

F values

One of the statistics associated with ANOVA as well as discriminant analysis. In discriminant analysis these are calculated from one-way ANOVA, with the grouping variables serving as the categorical independent variables. Each predictor, in turn, serves as the metric dependent variable in the ANOVA.

Factor scores

One of the statistics associated with factor analysis. These are the composite scores estimated for each respondent on the derived factors.

Variance

A statistical measure and a measure of variability. It is the mean squared deviation of all the values from the mean.