statistics Flashcards
name 4 different variables
- interval
- nominal
- ordinal
- ratio
what does nominal data consist of
discrete types of things (nouns)
what does ordinal data consist of
a ranked scale, e.g
- always, never, sometimes
what does interval data consist of
a numeric scale with NO TRUE ZERO VALUE
what is ratio data
numeric scale that includes ZERO
what is a numeric variable that is continuos with examples
can take any value in a certain set of values e.g temp, height, age
how are variables and values different
variable- the way that people in situations can vary
values- each instance has a single value for each variable
what is a numeric variable that is discrete with examples
can only take whole numbers e.g number of children
what kind of graph would be used for a numeric variable
histogram
what are three ways of reporting central tendency
mean, median, mode
what data used for nominal, ordinal, interval and ratio (mode, median, mean)
n- mode
o- mode and median
i- all
r- all
what are 4 variability measures (includes IQR)
- range
- inter quratile range
- variance
- standard deviation
what variability measure used in nominal, ordinal, interval and ratio
n- none
o- range and IQR
i- all
r- all
what units is variance in
cm2
what is s.d?
the square root of variance
categorical variables can be measured using…
nominal and ordinal scales
numerical variables can be measured using….
interval or ratio scales
what does s.d allow us to do?
see how spread out around the mean scores are in the data
what plot is used for quantitative data
graphically- scatter plot
qualitative data?
non- numerical info
- dont examine variables
- examines constructs, phenomonea and processes
quantitative data?
- numerical measures
- allows stats to be calculated
- observed through surveys, experiemnts etc
- e.g weight, height, temp
- finds trends, relationships and associations in data sets
definition of a casual hypothesis
formal statement predicitng specific change in one thing will produce specific change in another
why is there no independant variables in a correlational design
variables are not manipulated
univariate data
info that involves only one variable, allows analysis of single aspect without considering other variables
bivariate data
2 variable, allows examination of relationship between 2 variables
how is nominal values displayed
bar chart
how are ordinal values displayed
bar chart
what are interval values displayed
histogram
how are ratio values displayed
histogram
what is definition of variance
squared avergae distance between mean of all values in the data sample and the scores
what is s.d
square root of variance
in categorical data what 2 types of ways can you display this
-table cross tabulation
and
- bar chart
in quantitaive data what way can you show data
scatter plot
