Statistics Ap Psychology

Negatively skewed

A distribution of scores in which scores are concentrated in the high end of the distribution

Normal curve

A special frequency polygon in which the scores are symmetrically distributed around the mean, and the mean,mode,median are all located on the same point on the curve with scores decreasing as the curve extends from the mean

Frequency distribution

A table or graph that shows how often different number or scores appear in a particular set of scores

Descriptive statistics

A way of organizing numbers and summarizing them so that patterns can be determined

Bell curve

Alternate name for the normal curve which is said to be shaped like a bell

Inferential statistics

Analysis of two or more sets of numerical data to reduce the possibility of error in measurement and to determine if the differences between the data sets are greater than chance variation would predict

Mean

Arithmetic average of a distribution of numbers

Histogram

Bar graph showing a frequency distribution

Statistics

Branch of mathematics concerned with the collection and interpretation of numerical data

Bimodal

Condition in which a distribution has two modes

Range

Difference between the highest and lowest scores in a distribution

Positively skewed

Distribution of scores in which scores are concentrated in the low end of the distribution

Skewed distribution

Frequency distribution in which most of the scores fall to one side or the other of the distribution

Bimodal distribution

Frequency distribution in which there are two high points rather than one

Sample

Group of subjects selected from larger population of subjects

Polygon

Line graph showing a frequency distribution

Statistic

Measure of a central tendency or variability computed from a sample

Measures of variability

Measurement of the degree of differences within a distribution or how the scores are spread out

Median

Middle score in an ordered distribution of scores

Mode

Most frequent score in a distribution of scores

Parameter

Number representing some measure of central tendency or variability neighing a population

Measure of central tendency

Numbers that best represent the most typical score of a frequency distribution

Standard deviation

Square root of the average squared deviations from the mean of the scores in a distribution