PROABALITY AND SIG

Question 1

if the stats test is not sig the null hypo is accepted

Answer 1

• the null hypothesis states there is “no diff” or “no correlation” between the conditions
• the stats test determinds which hypo is true and thus accepts or rejects

Question 2

the null hypothesis is accepted or rejected at a particular lvl

Answer 2

• probability is a measure of the likehood that a particular event will occur, where 0 is a stats impossibility and 1 is a stats certainty.
• there are no stats certanties in psychology but there is a sig level - the point a which the null hypo is accepted or rejected.

Question 3

P value

Answer 3

• Probability refers to the likelihood of an event occurring. It can be expressed as a number (0.5)
• general psychologists use a probability level of 0.05.
• This means that there is a 5% probability that the results occurred by chance.

Question 4

using tables of critical value

Answer 4

• hypothesis one tailed (directional) or two tailed (non directional)

Question 5

The usual level of significant is 0.05%

Answer 5

• this means that 5% chance that the result in a particular study sample occurred
• even if there was no real difference in the population

Question 6

TYPE 1 ERRORS

Answer 6

• error involves a researcher falsely rejecting the null hypothesis and therefore falsely suggests an experiment has found an effect when it hasn’t
• OCCURS WHEN TOO HIGH E.G 0.05

Question 7

TYPE II (false negative)

Answer 7

• error is the opposite, where a researcher falsely accepts the null hypothesis and claims that there has been no effect found in an experiment when there has been.
• OCCURS WHEN THE SIG LVL IS TOO LINEINT

Question 8

what makes each error more likely

Answer 8

• a type one is more likely to be made if the sig lvl is too lenient (too high e.g 0.1 or 10%)
• a type 2 error is more likley if the sig lvl is too low (e.g 0.01 or 1%), as potentially sig values may be missed