STATISTICS FLASH CARDS

STATISTIC

A branch of mathematics which involves collecting organizing summarizing and analyzing data, it also involves drawing conclusions, making predictions from sample data and inferring sample results to the population

DESCRIPTIVE STATISTICS

A branch of statistics that includes collecting organizing and summarizing data

INFERENTIAL STATISTICS

A branch of statistics that includes analyzing data. It also involves drawing conclusions and/or making predictions from sample data to the population using probability.

RESEARCH QUESTION

A clearly defined question researches would like to answer

POPULATION

all subjects of interest (students, grades, fruits, ect)

SAMPLE

A subset of the population (EX: the population is using 2000 test subjects. A sample would use 10.)(A sample can be any amount but it’s not the same amount as the population)

RANDOM

each subject has an equal chance of being selected

REPRESENTATIVE

each subject is representative of the population

SIMPLE RANDOM SAMPLE

A sample in which each subject of the population has an equal chance of being selected

STRATIFIED SAMPLE

A sample in which subjects of the population are first divided into strata, then subjects are randomly selected from each Stratum

CLUSTER SAMPLE

A sample in which clusters of subjects are randomly selected from the population

SYSTEMATIC SAMPLE

A sample in which every xth subject of the population is randomly selected

CONVINCE SAMPLING

A sample in which the subjects of the population are selected conveniently

NONRESPONSE BIAS

bias that occurs when subjects do not respond to the questionnaire (survey)or cannot be contacted

RESPONSE BIAS

bias that occurs when a question is poorly worded, or when an interview can influence the subjects’ response

UNDERCOVERAGE BUAS

bias that occurs when representative subjects are not included in the sample selection process

VARIABLE OF INTEREST

A characteristic of the population

QUALITATIVE DATA

Data that can be categorized

QUANTITIVE DATA

Data that can be quantified

DISCRETE

quantitative values that are accountable

CONTINUOUS

quantity values that are measurable

BLIND

A technique where the subjects do not know whether they receive the treatment or placebo

DOUBLE BLIND

A technique were needed the subjects, nor the experimener(s) know which subjects received the treatment or placebo

FREQUENCY DISTRIBUTION

A table listing the possibilities of the variable of interest obtained from the sample along with their corresponding frequencies.

RELATIVE FREQUENCY

The frequency of each category divided by the same size (n)

RELATIVE FREQUENCY= frequency/sample size

PARAMETER

A numerical summary gathered from a population

STATISTIC

any miracle summary gathered from a sample

MEAN

A value that is calculated by summoning the values of the observations and dividing by the total number of observations

MEDIAN

A value that lies in the middle of the data. it divides the data set into two equal parts

MODE

The most frequently occurring observation