research methods

some random things ive forgotten

what is the definition of a self report

any data collection method that involves asking people to report their own thoughts, feelings or beliefs to researcher

what is self selected sampling

• individuals determine their own involvement in the study.

• for example, putting up posters, notice board ect asking people to volenteer

weaknesses of self selected sampling

• may be biased and unrepresentative of the target population because volunteers may be different in some way from non-volenteers e.g may be helpful or curious

• difficult to obtain large sample as it depends how good your advertising is

Strength of snow ball sampling

Can gain more participants

how to do the chi square test

1. calculate each row total and overall total

2. calculate unexpected frequencies for each cell using:

   • row total x column total / overall total

3. calculate observed value using formula (do for each and then add together to find final observed)

   • (observed - expected) / expected

4. calculate degrees of freedom using formula

   • (number of rows - 1) x (number of columns - 1)

5. identify critical value using df, direction of hypothesis and significance level

6. if observed value is more than or equal to critical it is significant then accept the alternative and reject the null

how to do binomal sign test

1. add positive and negative signs to each row of data e.g yes no = + no yes= - IGNORE the same (yes yes)

2. count each positive and negative sign assigned to each participant

3. the smallest of the total flow of direction scores is overall binomal observed value

4. calculate the N value (number of participants scores used not including the same)

5. identify critical value

6. in order to determine weather research is significant the observed has to be equal to or less than critical

how to do wilcoxon signed ranks

1. find the difference between each pair of scores for 2 IVs

2. rank difference from highest to lowest (ignore 0s, negative signs)

3. count how many positive and negatives in difference columns

4. calculate the observed value (using only least frequent sign) add scores from ranked order of difference

5. identify the N (number of differences)

6. identify the critical value from critical values table using n, significance level and direction of hypothesis

7. identify observed is significant (equal to or less than critical)

how to do mann whitney U

1. rank all scores from both IVs together from highest to lowest

2. calculate R1 by adding up ranks from IV1 only (across both)

3. calculate R2 by adding up ranks from IV2 only

4. calculate the observed value using the smallest R and one of the following formulas

   • U1= R1 - n1 (n1+1)/2

   • U1= R2 - n2 (n2+1)/2

5. identify critical values from critical value table

6. if U is significant only if observed is equal to or less than critical

how to do spear-mans rho

1. rank co-variable 1 then co- variable 2

2. calculate difference between ranks for each participant (co variables)

3. square each difference

4. add d² together

5. identify n

6. calculate observed value using:

   • 6 x D² / n (n² - 1)

7. identify critical values from critical values table

8. if observed is significant (more than or equal to critical value)