Statistics - True score (Classical test theory)

The true score is the score the truth that we try to estimate.

(Classical test|True score) theory asserts that raw scores are influenced by:

• bias,
• chance error,
• and true scores

Formula

$$\href{Raw Score}{Raw\,Score} = \href{True score}{True\,Score} + \href{bias}{Bias}+Error$$

where:

• True Score is the score in a perfect world
• Bias is a systematic error. Example: An instrument that will always measure with the same difference. It has an effect on the entire distribution (It shift it right or left)
• Error: is also known as Chance error, or random chance error (For example, measurement of body temperature, if someone drink a coffer before measuring its temperature)

Discover More
Statistics - (Univariate|Simple|Basic) Linear Regression

A Simple Linear regression is a linear regression with only one predictor variable (X). Correlation demonstrates the relationship between two variables whereas a simple regression provides an equation...
Statistics - Bootstrap Resampling

Bootstrap is a powerful resampling method for assessing uncertainty in estimates and is particularly good for getting their: standard errors and confidence limits. Why is the bootstrap useful? The...
Statistics - Confidence Interval

The definition of a confidence interval says that under repeated experiments 95% of the time this confidence interval will contain the true statistic (mean, ...). if we started the whole experiment over...
Statistics - Probability (of an event) / Likelihood

The probability of an event is the subjective chance that it will happen. The laws of probability are heavily build with therandom notion. A probability is a non-negative number between 0 and 100%. ...
Statistics - Raw score

A (raw|observed) score is the score in the original scale. not predicted (calculated) just observed (Classical test|True score) theory asserts that raw scores are influenced by: bias, ...
Statistics - Reliability (Reliable Measures)

How do we know how reliable our measure are. Raw scores (X) are not perfect. (Classical test|True score) theory asserts that raw scores are influenced by: bias, chance error, and true scores...