Probability and Significance Flashcards
(21 cards)
what is a hypothesis?
a hypothesis is a testable prediction. The hypothesis should always contain the independent variable (IV) and the dependent variable (DV)
what is a directional hypothesis?
predicts a difference/relationship from one variable to another in a specific direction
what is another name for a directional hypothesis?
one tailed
what is a non-directional hypothesis?
predicts a difference/relationship between the variables but not which way
what is another name for a non-directional hypothesis?
two-tailed
what is null hypothesis?
predicts there will be no effect between variables
is this a directional or non directional or null hypothesis:
boys are more aggressive than girl
directional
is this a directional or non directional or null hypothesis:
the quality of beer affects bar taking
non-directional
is this a directional or non directional or null hypothesis:
anxiety affects the level of adrenaline in the blood
non directional
what is a statistical test?
determines which of the hypotheses are true by either accepting or rejecting one of the hypothesis, to see whether result are down just to chance
statistics tests employ a level of …
what does this mean?
SIGNIFICANCE
this means that at this point the researcher can state that the relationship between the variables is due to more than just CHANCE in other words they can accept the alternative hypothesis (directional or non directional) and reject the null hypothesis
chance is equal to less that …..% and ….% that results are due to manipulation of variables.
5%
95%
why can we never be 100% about a particular research?
as they have not been tested on all members of the populating under all possible circumstances
when do lower level of significance occur?
this level becomes what?
this occurs when there is a juman cost e.g drug trails, or one off studies where the conditions could not be replicated again.
the level becomes 0.01 oe 1%
what is a type 1 error?
a type 1 error is also known as a false positive and occurs when a researcher incorrectly rejects a true null hypothesis, simply put false alarm
what is a type 2 error?
a type 2 error (or false negative) happens when you accept the null hypothesis when it should actually be rejected
researchers are more likely to make a type 1 error when level is too?
too lenient (0.1 or 10%)
they are also more likely to make a type 2 error if the level is too ?
too strict (0.01 or 1%)
what level do psychologists wort at to balance the chance of making errors (type 1 or type 2 error)
0.05 or 5%
to avoid a type 1 and type 2 psychologists need to alter the significance to ?
or do what?
0.05
sample size
