OUTLINE FOR CHAPTER
6
Estimation
- Introduction
- The two main kinds of estimation: interval estimation &
point estimation
- Estimation (interval or point) compared with the second main form
of inferential statistics: hypothesis testing
- Interval Estimation
- Sampling Error
- What a sampling error is . . . and what it isn't?
- Should we expect sampling error when a random
sample is drawn?
- Sampling Distributions and Standard Errors
- Sampling distribution . . . a frequency distribution showing
the results of multiple random samples of the same size drawn
from the same population
- Standard error . . . the standard deviation of a sampling
distribution
- Estimating the standard error from a single sample
- Estimate standard errors for different things: mean, proportion,
r, etc.
- The abbreviation SEM
- Reporting estimated standard errors in passages of text, tables,
and graphs
- Confidence Intervals
- What they look like (and how they appear in research reports)
- How they're constructed? . . . and 4 things that affect the
interval's width?
- How they ought to be interpreted?
- Their advantage over estimated standard errors
- Point Estimation
- How does one do point estimation?
- The big problem with point estimation: it's likely to fail due
to sampling error
- Places where point estimation is used by researchers:
- Reliability and validity coefficients
- As a core ingredient when building confidence intervals
- Warning Concerning Interval and Point Estimation
- If two numbers are separated by a "±" symbol, the number
that comes after the "±" symbol might be a SD . . . or it
might be an estimated standard error
- Standard errors are not determined, they're only
estimated
- Sometimes (as when dealing with r), the sample statistic will
not be located exactly halfway between the end points
of the confidence interval
- Neither interval estimation nor point estimation can be expected
to work if based upon nonrandom samples
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