Unit 3 Flashcards
Types of scores and variables transformation
What are direct scores?
Direct scores, also known as “raw dat”, represent the data obtained directly from a measuring instrument
Provide an example of direct score
A direct score could be 20 correct answers on a 100 question test
What are the limitations of direct scores?
Direct scores offer limited information, lack independent interpretability, require a reference point, aren’t comparable bbetween different instruments and need transformation for meaningful analysis.
What is a differential score?
A differential score is a transformed score obtained by subtracting the mean from a direct score (x - x̄).
How do you interpret the sign of differential score?
A positive sign signifies a score exceeding the mean, while a negative sign indicates a score below the mean.
What is a limitation od differential scores?
Differential scores do not consider data variability
How are differential scores primarily used?
Differential scores are mainly used in the calculation of standard scores and other statistical measures like variance or standard daviation, rather than as a standalone measure.
What are standard scores?
Standard scores illustrate the difference between an individual’s score and their reference group’s mean, accounting for data dispersion
What is another term for standard scores?
Another term for standard scores is Z scores.
What does converting a direct score into a standard score achieve?
Converting a direct score into a standard score standardizes or typifies the distribution, facilitating comparions between different distribuitions and scores of different natures
What is the purpose of transforming data to a normal distribution using standard scores?
Transforming data to a normal distribution enables comparisons between scores from different groups and variables
In a standardized distribution, what is the mean always?
In a typified distribution, the mean is always 0
In a typified/standardized distribution, what is the standard deviation always?
In a typified distribution, the standard deviation is always 1.
What does standard score indicate?
A standard score reveals how many standard deviations a scores (x) deviates from the mean of its group
Write the formula for calculating a standard score (Z score).
Z = (x - x̄) / S
If a subject’s score is equal to the mean, what will their standard score (Z) be?
If a subject’s score equals the mean, their standard score (Z) will be 0.
What is the typical range of standard scores?
Standard scores typically fall between -3 and 3.
What does a positive standard score indicate?
A positive standard score means the scores is above the mean.
What does a negative standard score indicate?
A negative standard score means the score is below the mean.
What is the mean of standard scores always?
always 0.
What are the standard deviation and variance pf standard scores always?
The standard deviation and variance of standard scores are always 1.
What 3 keys terms relate to transforming direct scores to consider data dispersion?
The terms are direct score, differential score, and standard score.
What is a normal distribution?
A normal distribution is a statistical concept where data is symmetrically distributed around the mean, with mean, median, and mode all being equal.
