MHB Standard deviation, raw score etc

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The discussion focuses on understanding the concepts of raw score, observed score, true score, and confidence intervals (CI) in relation to a test with a mean of 80, a standard deviation of 5, and a standard error of measurement of 3. Jim's score of 85 is identified as both the raw and observed score. The true score cannot be determined due to inherent measurement error. The confidence interval at 68% is calculated as the mean plus or minus the SEM, while the 95% CI is calculated using 1.96 times the SEM. The conversation emphasizes the importance of these statistical measures in interpreting test scores.
saharalynne
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-3 SD -2 SD -1 SD 80 +1SD +2 SD +3 SD
mean
65 70 75 85 90 95

The test has a mean of 80, a standard deviation of 5 and a standard error of measurement of 3.
Information given: Mean = 80 SD = 5 SEM = 3 Jim’s score = 85

I need to know the raw score, observed score, true score, ci for 68 and 95
 
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saharalynne said:
-3 SD -2 SD -1 SD 80 +1SD +2 SD +3 SD
mean
65 70 75 85 90 95The test has a mean of 80, a standard deviation of 5 and a standard error of measurement of 3.
Information given: Mean = 80 SD = 5 SEM = 3 Jim’s score = 85

I need to know the raw score, observed score, true score, ci for 68 and 95

Hi saharalynne! Welcome to MHB! (Smile)

The raw score is the original untransformed score, which is the same as the observed score.
We can never know the true score, since what we measure always contains an unknown error.

The confidence interval (CI) at confidence level 68% is the interval from Mean - SEM to Mean + SEM.
And the CI at confidence level 95% is the interval from Mean - 1.96 x SEM to Mean + 1.96 x SEM.

Can you tell what each of those are? (Wondering)
 
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