Sign Test Flashcards
Descriptive statistics and inferential statistics
Descriptive statistics are statistics such as central tendency and dispersion
Inferential statistics is when you infer results from a smaller sample such as study showing the taller people are smarter for that sample so it can be inferred this is true for all people (it isn’t)
In order to make an inference about the target population you have to see if our results are significant,
Inferential statistics can show the probability of that a set if data has happened by chance or due to the IV. The accosted level of something occurring by chance is less then 5% or else the hypothesis can’t be accepted
What is the Sign test
There are rules when a particular inferential statistic can be used, the sign gets can only be used when there is one group of participants and the data must be quantitative.
Sign test method
You have the same participants but two data sets with numbers from one to ten for each score,
1) if the hypothesis is directional a one tailed test is used of it is non directional a two tailed test is used
2) record the differences between each pair and record wether the difference is positive or negative
3) add up the positive signs and the negative signs and choose the smaller value, this is the S value so if the is 7 positive and 3 negative then S=3. 0s are not counted, this is called the calculated value.
4) N is the total number of scores ignoring any 0 values. When the hypothesis is directional a one tail test is used. By looking at the table at the row where N value is the same as the one we have and under the same test type we get a value. The calculated result must be equal or less for it to be significant, if it is directional then we need to check if it was on in the right direction but seeing if there was more pluses or minuses and choosing the suitable hypothesis.
