問41
頻出度★★★
システムのテスト中に発見したバグを, 原因別に集計して発生頻度の高い順に並べ, 累積曲線を入れた図表はどれか。
平成31年度 春期 ITパスポート試験 問41
ストラテジ系企業活動 › 業務分析・データ利活用
This question's explanation and your answers so far.
解説
問 41
Incorrectア
A scatter plot places the values of two quantities (for example, temperature and sales) as points on a plane to see whether they are correlated and any trend between them. It neither arranges counts by cause in descending order nor draws a cumulative curve, so it does not apply.
Incorrectイ
A cause-and-effect diagram (fishbone diagram) organizes the factors behind a single result (characteristic) into a fish-bone shape of large and small bones to systematically uncover the causes. It has nothing to do with tallying counts, sorting by frequency, or a cumulative curve, and it is not a chart that visualizes quantities.
- ウ
正解 A Pareto chart arranges items (here, the causes of bugs) as bars in descending order of count and overlays their cumulative ratio as a line (the cumulative curve). It matches all three features in the stem: tallying by cause, arranging in descending order of occurrence frequency, and adding a cumulative curve. This lets you see at a glance which causes account for most of the total, and it is used in techniques such as ABC analysis to identify the vital few causes that deserve focused countermeasures. The correct answer is therefore ウ.
Incorrectエ
A histogram divides data into several intervals (classes) and shows the frequency of each interval as a bar to see the spread and shape of the distribution. The bars are arranged in order of the class values, not re-sorted in descending order of frequency, and by default no cumulative curve is drawn, so it does not meet the stem's conditions.
ここがポイント
- Pareto chart = bars in descending order of count plus a line of the cumulative ratio (the cumulative curve). It is the tool used in ABC analysis to find the vital few causes.
- Distinguish among the QC seven tools: do not confuse it with the scatter plot for correlation, the cause-and-effect diagram for uncovering factors, or the histogram for the spread of a distribution.
用語