quanititive data analysis Flashcards
what type of data is the mean
interval or ratio
evaluate the mean
+ uses all values
- misrepresentative is extreme variables
what type of data is the median
ordinal
evaluate the median
+ not affected by extreme scores
- doesnt work with small data sets
- not all values reflected
what types of data is the mode
nominal
evaluate the mode
+ useful when data in categories
+ number does actually occur
- nothing about other values
- hard to describe data with several modes
evaluate the range
+ easy to calculates
- only 2 values
- extreme can distort
evaluate standard deviation
+ every score, not distorted
- hard to calculate
what are bar charts
discrete data
categories x
mean/ frq y
do not touch bars
what are line graphs
bar chart with tops of bar represented by dot
compare changes over time
what are histograms
continuous data, columns touch because each one forms a single score on a reflected scale
scores x
height = freq
what is a frequency polygon
alternative to histograms
midpoints of each column on histogram
compare 2+ conditions
what are pie charts
description of parts that make up whole
what are scattergrams
measure relationship between 2 variables
plot x where variables meet
correlation
what are frequency tables
organise values into groups when large numbers
patterns clearner
when to use chi squared
test of difference
independant group
nominal ordinal or interval ratio data
when to use a mann whitney u
test of difference
independant groups
nominal, ordinal or interval ratio data
when to use a wilcoxon test
test of difference
repeated or matched pairs
nominal, ordinal, interval ratio data
when to use a soeamans rho
test of correlation or association
