テーマ： reporting
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技術報告における測定の不確かさと有効数字
不確かさを示さない測定値は不完全です。測定を繰り返し、平均と平均の標準偏差、実行回数を報告します。不確かさを有効数字1桁か2桁に丸め、値も同じ桁にそろえ、区間の意味を示します。不確かさが裏付ける範囲を超えた桁はノイズです。
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p-values: what they measure and what they do not
A p-value is the probability, computed under the whole statistical model including the null hypothesis, of a test statistic at least as extreme as the observed one. It is not the probability that the null is true, not the probability that chance produced the result, not a measure of effect size, and 0.05 is a convention rather than a boundary between truth and noise.
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Log scales, truncated axes and other ways a chart misleads
A log axis turns equal ratios into equal distances and is the right choice for data spanning orders of magnitude, but it hides absolute differences and cannot show zero; a bar chart whose axis does not start at zero lies about proportions. Label the scale, keep the baseline for bars, and use symlog for counts that include zero.
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信頼区間の概要：区間が示すこと、示さないこと
95%信頼区間は、標本抽出を繰り返したときに95%の区間が真の値を含む手順から得られます。特定の区間は真の値を含むか、含まないかのどちらかです。幅は標本数の平方根に応じて狭まり、ばらつきとともに広がります。データと整合する値の範囲として読み、各推定値と併記し、比較時には差の区間を計算します。
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Reporting a performance finding without over-claiming: baseline, incident window, tool and interval
A performance write-up an agent can trust states the baseline and incident numbers with the same tool and interval where possible, names the exact time window, keeps read facts visibly separate from interpretation, and lists what was ruled out rather than implying an exhaustive investigation.
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Variance, standard deviation, MAD and IQR: reporting the spread
A location without a spread is half a number. The standard deviation describes spread well for roughly normal data and is dominated by the tails otherwise; the interquartile range and the median absolute deviation describe the bulk. Name the measure, give the sample size, use the n−1 form for estimates from samples, and never label an error bar with a bare ±.
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Mean, median and mode: choosing a summary statistic that does not mislead
The arithmetic mean is pulled by skew and outliers, the median ignores how far the extremes go, and the mode only makes sense for categorical or clearly peaked data. Choose by the shape of the distribution and by the question asked, print the count next to every summary, and never average ratios or percentiles.
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Simpson's paradox and base-rate neglect in reports
Two arithmetic effects make a correct table support a wrong sentence: an association can reverse when a population is split into groups that were mixed in different proportions, and a signal's accuracy says little about what a positive signal means until the base rate is known. Ask how groups were mixed and keep denominators visible.
機械可読： JSON