| back 1 - Require assumptions about population parameters
- Require numerical scores
- Can be used to calculate mean
& standard deviation
- Use ratio & interval data
- Testing hypotheses: Use population parameters
|
| back 2 - DO NOT require assumptions about population parameters
- DO NOT require numerical scores; use categories, names, and
groupings'
- CANNOT be used to calculate mean & standard
deviation
- Use nominal and ordinal data
- Testing
hypotheses: DO NOT state specific, numeric, population
parameters
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front 3 When to use nonparametric tests | back 3 - When Simplicity is Needed
- Sometimes categories are
simpler than scores (and still useful)
- When
scores violate assumptions of parametric tests
- For
instance, parametric tests require normal distributions
- When variance is extremely high
- Extreme
variance makes statistical significance unlikely
- Categories allow diverse scores to fit (ex. High, Medium,
Low)
- With Indeterminate or Infinite
Scores
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front 4 Research Designs for T Tests | back 4 - Single Sample
- Uses a single sample to make inferences
about a single population
- Two Unrelated Samples
- Uses two samples to make
inferences between two unknown populations
- Two Related Samples
- Uses one sample with each
individual tested in two treatment conditions to make inferences
about mean population differences
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front 5 T Test: Hypothesis testing | back 5 - GOAL: Use sample from treated population (treated sample) to
determine whether treatment has effect.
- Population mean is
UNKNOWN
- Sample Mean is KNOWN, as is estimated standard
error
|
| back 6 - Null hypothesis states that there is no treatment effect
and that the population mean is unchanged
- Null
hypothesis provides a specific value for the unknown population
mean
|
| |
| back 8 - Single Sample
- Uses sample data (one sample) to test a
population mean
- Independent Samples
- Uses data from two separate samples to evaluate mean
difference between two different treatment conditions or
populations
- Two sets of data
- Completely separate
(independent) groups of participants
- Repeated Measures Designs
- Uses two sets of data from
the same sample of participants to evaluate mean difference
- Two sets of data
- The same group of
participants
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front 9 T Test: Types (reporting differences) | back 9 -
Independent
Samples:
- Since it involves two separate
samples, extra notation is needed
- Subscripts are used,
with number indicating which sample (1 or 2)
-
n 1, n
2 (sample size); M 1,
M 2 (means), SS
1, SS 2 (sum of
squares; μ 1 - μ 2
(population mean difference)
-
Repeated Measures
Designs
- Uses sample mean difference
(M D) to estimate population mean
difference (μ D)
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front 10 Independent Samples: Advantages and Disadvantages | back 10 -
Pro’s:
- No potential for order effects
- No potential for time-related factors
-
Con’s:
-
Less efficient (more participants
needed)
- Less ideal for studying changes over time
- Potential problems with individual differences
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front 11 Repeated measures: Advantages and Disadvantages | back 11 -
Pro’s:
- More efficient (fewer participants
needed)
- Good for studying changes over time
- Reduces problems caused by individual differences
-
Con’s:
- Potential for order
effects
- Potential for time-related factors
|
| back 12 - T-test: can only compare two treatments
- ANOVA: can
compare 2 or more treatments
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| back 13 - Definition
- Analysis of Variance
- It is a
hypothesis testing procedure used to evaluate mean differences
between two or more populations or treatments
- Uses
sample data to make inferences about populations
- FACTOR
- The variable (independent or quasi-independent)
that designates the groups being compared
- LEVELS
- Individual conditions or values that make up a
factor
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| back 14 - Single-Factor
- Studies that have one independent
variable (one factor)
- Independent-Measures
- Separate group of participants for each treatment being
compared
- Repeated-Measures
- Same group
of participants is tested in all treatment conditions
- Two-Factor
- Studies that have two independent
variables (two factors)
- Can address different questions
than single-factor designs
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front 15 Null Hypothesis for ANOVA | back 15 - States that there is no treatment effect and that the
population mean is unchanged
- Provides a specific value for
the unknown population mean
|
| back 16 - Testwise Alpha
- The risk of a Type I error, or alpha
level, for an individual hypothesis test
- This is what
we’ve talked about for the whole semester
- Experimentwise Alpha
- Is the total probability of a Type
I error that accumulates when several hypothesis tests are used
in a single study
- Typically larger than testwise
alpha
- Is the reason why multiple t-tests should be run to
compare three groups (use ANOVA instead)
|
| |
| back 18 - What are they?
- Additional hypothesis tests that are
run after an ANOVA to determine exactly which
mean differences are significant and which are not
- When to use them?
- When you have a significant
F statistic and there are more than two groups
- F-statistic does not indicate where the
significance is
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front 19 Chi-Square Test for Goodness of Fit | back 19 - Uses sample data to test hypotheses about the shape or
proportion of a population distribution
- Determines
how well sample proportions fit population proportions of null
hypothesis
|
front 20 Chi-Square Test for Goodness of Fit: Data Presentation | |
front 21 Types of null hypotheses for Chi-Square | |
front 22 Types of null hypotheses for Chi-Square | |
front 23 Correlational Research Strategy | back 23 - Two or more variables are measured to obtain a set of scores
(usually 2) for each individual (or source)
- Measurements
are examined to identify patterns that exist between the variables
and to measure the strength of the relationship
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front 24 What correlations describe | back 24 - The direction of the relationship
- Positive or negative
relationships
- The form of relationship
- Linear (using Pearson correlation)
- Monotonic (using
Spearman correlation)
- The consistency or
strength of relationship
- How close the relationship is to a
perfect linear or a perfect monotone relationship
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front 25 Correlational Vs. Experimental | back 25 -
Correlational
-
Goal: Demonstrating the existence of a relationship
between variables (not explaining)
- NO
manipulating or controlling variables
- Measures two
different variables
-
Experimental
-
Goal: Demonstrating cause and effect,
explaining relationship between variables
- DOES
manipulate and control certain variables
- Usually only
one measured (dependent) variable and looks for differences
between two or more groups of scores
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