Stats Test Flashcards
What does statistical testing provide?
- provides a way of telling whether differences OR relationships between variables are ‘statistically significant’ or not.
e.g enough data to know the difference can be accepted as a universal law of behaviour (HASN’T OCCURRED BY CHANCE)
What do stats tests determine for a hypothesis?
- determine whether a hypothesis should be accepted or rejected
What does a statistically significant difference or relationship mean or NOT mean?
a hypothesis is accepted - means that a vast majority of the population the observed difference or relationship can be applied
DOESN’T MEAN that it can be applied to every single individual in society (extreme cases cant be accounted for)
Why is population validity so important?
- crucial in ensuring a study is representative of the wider population as possible
- ensures that the law is truly universal
What is the sign test used to assess?
used to assess the statistical significance of differences when the same set of participants experience BOTH conditions/tested TWICE
When should the sign test be used?
(*****)
SNoRD - NO o (used to make a phrase)
S -sign test (name of the test)
N - nominal data (data can be categorised by particular characteristics = word list A, word list B)
R - repeated measures (when participants have experienced BOTH conditions)
D - differences (when there’s a difference rather than an association)
What are the 3 steps for carrying out a sign test?
1) Find your calculated value of S
- look at the results table - take away column A from B (notes the sign (+ or - or = )
- tally up the number of pluses, minuses + equals
- select the sign that appears least frequently
that number is the CALCULATED VALUE S = 5
2) Find the critical value
- always a table of critical values
- 3 things to know when selecting the correct critical value
a) number (N of participants in the study) but subtracting participants with no difference (minus all participants with an equal sign)
e.g 18 participants with 0 people with an equal 18-0 = 18
b) is hypothesis ONE (prior research) or TWO (no prior research) tailed
c) what is the level of significance being used - ACCEPTED LEVEL OF PROBABILITY is 5% (0.05)
- choose a correct value from the table
What can a hypothesis shown to be proven statistically significant by the sign test be?
the hypothesis can be ACCEPTED
What are the 3 levels of measurement and what type are they?
Nominal = data in form of CATEGORIES
Ordinal = data in RANK POSITION
Interval = data in FIXED UNIT OF MEASUREMENT
What are the measures of central tendency for 3 types of data?
(Mean,Mode,Median)
Mode = noMinal
Median = oridiNal
Mean = intErval
Why do we use STATISTICAL TESTS?
- measure if results were due to CHANCE or if they are STATISTICALLY MEANINGFUL
chance = happens as a ONE OFF (wouldn’t usually see this particular behaviour
