Results Flashcards
measurement
Assigning numbers to objects or events
instrumental measurement
◦ Audiometer ◦ Nasometer ◦ Visipitch
quantified measurement
◦ Hearing level ◦ Nasality ◦ Voice Fo
behavioral measurement
◦ Tests ◦ Surveys ◦ Questionnaires
nominal
attributes are only named -Nominal data deals with names, categories, or labels. -Data at the nominal level is qualitative
ordinal
-attributes can be ordered -Data at this level can be ordered, but no differences between the data can be taken that are meaningful. Subjects were classified based on degree of hearing loss 1 = Mild 2 = Moderate 3 = Moderately-Severe 4 = Severe 5 = Profound
interval
distance is meaningful -The interval level of measurement deals with data that can be ordered, and in which differences between the data does make sense. -There is an equal distance between each value. -Data at this level does not have a starting point. ex) Words were presented at 3 different levels: ◦ Soft = 40 dB ◦ Medium = 60 dB ◦ Loud = 80 dB
ratio
absolute zero
measurement accuracy
Observed score = true score + error X=T+E - True score obtained under ideal conditions - Error occurs because “ideal” never exists - Measurement with less error = more reliable
unsystematic (random) errors
- Random errors in experimental measurements are caused by unknown and unpredictable changes in the experiment. - Random errors often have a normal distribution
sources of random error
- Fluctuation in equipment - Changes in the environment - Changes in the subject - Changes in the observer - Measure is limited sample of behavior that is not stable
systematic error
- Systematic errors usually come from the measuring instruments. ◦ There is something wrong with the instrument ◦ The instrument is used incorrectly by the experimenter - There’s something wrong with the examiner :(
reliability
Can we depend on a measurement? Precision and Accuracy
precision
◦ Stability of the measurement ◦ Reproducibility
accuracy
◦ Closeness of obtained score to expected or true score
how to estimate the reliability of a measurement
- Test-retest - Coefficient of stability - Equivalence of Measurement ◦ Alternate equivalent forms - Coefficient of equivalence
internal consistency
◦ How well each item is measuring same thing?
standard error of measurement
- It is an estimate of how often you can expect errors of a given size - Based on the reliability coefficient and the test’s standard deviation - Low SEM = high level of score accuracy
inter-observer reliability
◦ Two or more observers measuring the same event ◦ Equivalence
intra-observer reliability
◦ One observer measuring event at different times ◦ Stability
coefficient of correlation
• A correlation coefficient is a statistical summary of the relation between two variables.
• It is the most common way of reporting the answer to such questions as the following:
▫ Does this test predict performance on the criterion test?
▫ Do these two tests measure the same thing?
▫ Are these two constructs related?
validity of measurements
Degree to which the measurement measures what it is supposed to measure
Are we really measuring what we intend to measure?
Truthfulness of measure.
internal validity
Is researcher justified in concluding cause/effect
relationship?
▫ Were variances controlled to avoid contamination
of results?
external validity
Can findings can be generalized to population as a whole?