CP #1

discrete

No possible values between adjacent unites n the scale EX - # of children in a familuy - there cant be 1.5

Bar graph

Frequency distribution of ordinal or nominal data Bars do not touch Shows the relative number of frequency - or relative frequency for discrete data vertical bar centered over each interval adjacent bard do NOT touch

Histogram

Interval or ratio data Height corresponds to frequency class bar begins and ends at real limits For continuous data vertical bar centered over each score interval adjacent bars touch

Frequency Polygon

Interval or ratio data similar/identical to histogram excet instead of bars there is a mid point of each interval

Measures of variability

Range Standard Deviation Variance Variability - how far about scores are, quantifies extent of dispersion Range - high minus low Standard deviation - a measure of variability that gives the average deviation (how far away the raw score number is from the mean) of a set of scores about the mean Variance - standard deviation squared

Central Tendency

The average, middle, or most frequent value f a set of scores. The purpose is to quantify distributions in order to compare them A measure that provides a single score to represent the entire group Mean, Median and Mode Mean - average and its balancing the scores of distribution (balances out the values of the score) Mean can be affected by outliers which could make it less representative of the data set Median is more reliable than the mode. Mean - sensitive to extreme scores, least subject to sample variation Median - less sensitive to extreme scores than mean, more subject to sampling variation than mean but less than mode Mode - not sensitive to extreme scores but very subjective to sampling variation Mode as a measure of central tendency - nominal

Inferential statistics

Used to draw conclusions from the sample data n order to make a statement about the population of interest Techniques that use the obtained sample to infer to populations EX - probability, test statistics, hypothesis testing, estimate, f stat, chi square, Students t test, ANOVA

Descriptive statistics

Used to organize, summarize, and simplify data in order to identify meaningful patterns of data Techniques that are used to describe or characterize obtained data EX - counts, percentages, average, range, correlation, central tendency, variability, an annual stockholders repots

Criterion

difference between groups on DV

interval

equal intervals, represent raw score magnitudes, there are equal intervals between adjacent intervals. No absolute 0. Ordinal with equal variances arbitrary - artificially constructed standardized construction EX - anxiety measured using a standardized test SAT scores GPA RANGE

expost facto

not and experiment No manipulation we dont know the cause no random assignment more likely to have a confounding variable takes place of IV bc no manipulation EX-self slected groups coffee example

ordinal

rank order Ranking of data numbers represent rank orders rather than raw score EX - likert scale satisfaction with a product using likert scale social ranking of students

Nominal

sets of categories in no particular order category for units - naming not ranking EX - race, gender, ethnicity, major,

confounding

systematic differences between groups person conducting better health to begin with

zscore

the standard score a transformed score that designated how many standard deviation units the score is above or below the mean x-mu/sigma Purpose- compare scores that usually wouldnt be comparable in conjunction with normal curve - it allows us to determing the percentge of scores that fall above or belo any score characteristics - same shape as the set of raw scores mean mu=0 sigma =1

Percentile

the value on a measurement scale below which a specified percentage of the scores in the distribution fall Percentile point= XvL + (i/FvL)(cumfvp-cumfL)

continuous

theoretically can have an infinite number of values between adjacent units on a scale EX - weights and height The time at which you eat time of the day

ratio

true zero Highest level of measurement Units represent raw score magnitudes equal intervals Absolute 0 Non arbitrary, meaningful scale, physical scale Anything time and weight EX - reaction time in a video game number of punches in a minute - what if there are no punches soda consumed per day - some people might not drink soda

nuisance

variability randomly distributed within groups