Making Inferences: Confidence Limits and Statistical Significance

Question 1

the name given to the standard
deviation of the sampling distribution.

Answer 1

standard error

Question 2

probability always goes from____

Answer 2

0 to 1

Question 2

*that is if we carry out the same experiment over and
over again we will get slightly different results every
time.

Answer 2

The SE is the SD of that sample of scores.

Question 2

An event which has a probability of____ will not happen.

Answer 2

zero

Question 3

probability of a result occurring if
the null hypothesis is true, not the probability that the
null hypothesis is true.

Answer 3

Probability value

Question 3

if we are
looking for a result in one direction only.

Answer 3

One tailed (or directional) hypothesis

Question 3

An event which has a probability of ____ will happen, no
matter what.

Answer 3

1

Question 3

______is counter-intuitive.

Answer 3

probability

Question 4

It is ______ because we like to believe that we
know things rather than making probability statements
about them.

Answer 4

counter-intuitive

Question 5

symbolized by H₁. The
hypothesis that claims the differences in results between
the conditions is due to the independent variable.

Answer 5

alternative hypothesis

Question 5

value or cut-off we use
before we decide to reject the null hypothesis.

Answer 5

α (alpha – Greek Letter)

Question 5

symbolized by Hₒ. Logical counterpart
to the alternative hypothesis. It either specifies that
there is no effect, or that there is real effect in the
direction opposite to that specified by the alternative
hypothesis.

Answer 5

null hypothesis

Question 5

When the probability is found to be below 0.05 (or
whatever cut-off we are using) it is described as____

Answer 5

statistically significance

Question 6

somewhat arbitrary, but is the
convention that is used throughout much of science.

Answer 6

0.05 (1 in 20 0r 5%) –

Question 6

is deemed rare enough that we can trust it
but not so stringent that it is impossible to achieve.

Answer 6

one in 20

Question 7

if we are
looking for a result in either direction.

Answer 7

Two-tailed (or non-directional) hypothesis

Question 7

Psychologists accept findings that are likely to have
occurred by chance no more than 5 out of 100 times.

Answer 7

(P = to or < .05)

Question 8

Determining how likely it is that the result could have
occurred by chance.

Answer 8

statistical significance

Question 8

the probability that the
pattern of data that was observed did not occur by
chance.

Answer 8

statistical significance

Question 9

indicates that the probability that the
observed finding occurred by chance is less than 5 in
100.

Answer 9

alpha level

Question 10

A statistically significant result does not necessarily
have “meaning”, and is not necessarily “important”, it
just means that there is a less than 1 in 20 probability
that the results would have occurred if the______were correct.

Answer 10

null hypothesis

Question 11

If you find that your p-value is below 0.05, you reject
the null hypothesis. This does not mean to say that you
can accept the _____

Answer 11

alternative hypothesis

Question 11

the range of values which are
the likely range of the population value.

Answer 11

Confidence Intervals

Question 12

Similarly, if you find that your p-value is above 0.05, you
can not say that you can accept the_____. All
you can say is you have not found evidence to reject it

Answer 12

null hypothesis.

Question 12

accept the null hypothesis

accept the alternative hypothesis

reject the alternative hypothesis

Answer 12

wrong

Question 12

when we reject the null hypothesis
because there is only a low probability of the result
occurring if it is true, but it might actually be true after
all.

Answer 12

type 1 error

Question 13

reject the null hypothesis

fail to reject the null hypothesis

Answer 13

correct

Question 13

value that we suspect in the population

Answer 13

mean

Question 14

– the other logical error when we fail to
reject the null hypothesis when it is not true.

Answer 14

type II error

Question 14

If we want to estimate the statistical significance of our
results (that is, the probability of our result occurring if
the null hypothesis is true), then we need to get back to
the_____

Answer 14

standard error

Question 14

If our sample is large, the distribution will be normal.

Answer 14

central limit theorem

Question 14

If our sample is not large, then the distribution is not
normal, instead it follows a shape called the____

Answer 14

t-distribution

Question 15

value for our mean in the sample

Answer 15

score

Question 16

– the number of scores that
are free to vary in calculating a statistic.

df = N – 1

Answer 16

Degrees of Freedom or df

Question 17

the largest and smallest values in the interval.

Answer 17

Confidence Limits

Question 18

We usually calculate 95% confidence limits which match
the 0.05 significance level

Answer 18

(alpha level α )