How to Use Center Score Calculator (McIsaac Version)
- Enter the score list separated by commas, spaces, or line breaks.
- Enter optional weights in the same order. Missing or invalid weights are treated as 1.
- Choose raw weighted mean, standard score, or McIsaac modified weighting.
- Calculate to see the center score plus supporting statistics such as count, mean, and standard deviation.
Raw weighted mean = Σ(score x weight) / Σ(weight)
Standard score = 50 + 10z
McIsaac-style center score = Σ(score x center weight) / Σ(center weight)
- Raw mode calculates a weighted mean: sum(score x weight) / sum(weight).
- Standard mode transforms the weighted mean using 50 + 10z, where z compares it with the score-list mean and standard deviation.
- McIsaac modified mode gives more influence to scores near the median and less influence to distant scores.
- This makes the McIsaac-style result less sensitive to extreme high or low values than a plain mean.
Use Cases for Center Score Calculator (McIsaac Version)
- Summarizing a group of test scores when outliers should not dominate.
- Comparing raw and standardized scoring schemes.
- Experimenting with custom weights for assignments, rubrics, or evaluation panels.