MODULE 3: DESCRIPTIVE STATISTICS AND DATA ORGANIZATION

frequency distribution

a table in which all of the scores are listed along with frequency with which each occurs. a way of presenting data that makes the pattern of data easier to see.

relative frequency

the proportion of the total observations included in each scores.

class interval frequency

individual scores are combined into categories and then listed along with the frequency scores in each individual

class interval

group pf scores

class limit

end numbers of class interval

class frequency

number of scores falling in each class interval

class size

the diffrence between upper limit and preceding class

class mark

the midpoint of class interval

bar chart

used to show distribution of nominal or categorical variables

vertical bar graph

used to compare levels of nominal variables

horizontal bar graph

used to compare levels of ordinal variables

pie chart

used to show what part of the whole each level of category variable is.

line graph

used to visualize the value of variables over time

histogram

uses intervals of value of variable or numerical data and there is no gap between bars

stem and leaf plot

a table in which data value is splitted into stem and leaf

leaf

it is ones digit

stem

preceding digit to ones digit

mean

most commonly used measure of central tendency. It is calculated by adding all the scores together and dividing the sum by the total number of scores.

median

used in situation in which mean might not be representative of distribution and when there are extreme score in distribution. can be found by looking in the mid number

mode

it is the score that frequently appears in a set