
慶英会 塾長|慶應義塾大学卒・英検1級
中高一貫校の学校英語・NEW TREASURE・英検対策を専門とするオンライン個別指導塾です。塾長紹介
英検準2級プラスの説明文長文では、correlation(同時に変化する・関連が見られる)とcausation(一方が他方の原因である)を区別しましょう。改善策の後で数値が変わっても、天候・人数・テスト問題が同時に変わったなら、改善策だけを原因と断定できません。慶英会独自4長文24課題と全文和訳・全解説を掲載します。
対象:準2級プラスから2級へ進む中高生。調査・グラフ・説明文の根拠を正しく読むための補助教材です。数字と場面は独自の架空設定で、英検公式過去問や実在する研究結果ではありません。
何を観測し、何を推測したか
| 情報 | 読むポイント |
|---|---|
| observed change | 実際に変化した数値・事実 |
| possible explanation | 考えられる原因の一つ |
| another factor | 同時に変わった別の条件 |
| cannot conclude | まだ断定できないこと |
この教材は因果推論を断定する訓練ではなく、本文に記載された根拠の範囲を保って答える練習です。
4長文24課題の進め方
- 実際に観測した変化を探す。
- 4択の内容一致3問を解く。
- 別に変わった条件を挙げる。
- 根拠を超えた因果関係の断定を訂正する。
- 重要な一文を正確に訳す。
独自長文1|授業前の語彙復習と小テスト
One class began spending five minutes reviewing vocabulary at the start of English lessons. Four weeks later, the class’s average quiz score was higher than before. However, the later quiz contained different questions, and the teacher had also introduced a new textbook during those weeks. No other class was tested under the same conditions. The students’ scores and the new review routine changed during the same period, but the school could not tell which factor explained the difference. The teacher planned to compare classes using the same quiz before describing the review as an effective method.
- What changed during the four weeks?
- Only the room number
- The review routine and textbook
- The school name
- The examination date only
- Why is the cause of score improvement unclear?
- No students attended
- The school was closed
- Different quiz questions and a new textbook were involved
- All students got the same score
- What is planned for a more reliable comparison?
- Using the same quiz for comparable classes
- Removing all English lessons
- Publishing a guaranteed result
- Counting only the top student
- 実際の変化と、ほかに変わった条件を英語で整理する。
- 誤った断定を修正する:The review alone proved effective for every class in the school.
- 英文を訳す:The school could not tell which factor explained the difference.
本文全文和訳・6課題の正答と詳しい理由
【全文和訳】一つのクラスは授業冒頭に5分間の語彙復習を導入し、4週間後の平均点は以前より高かった。しかし後の小テストは問題が異なり、その期間に新教科書も導入されていた。条件をそろえた他クラスの調査はない。復習と点数が同期間に変化したことは分かるが、復習が唯一の原因とは判断できず、教師は同一テストで比較する予定。
- B:The review routine and textbook。review and textbook changed।
- C:Different quiz questions and a new textbook were involved。different quiz and new book।
- A:Using the same quiz for comparable classes。compare classes same quiz।
- 観測:The later average quiz score was higher in one class.
【別条件】The textbook and quiz questions changed too.
【判断の限界】The results do not prove that five-minute reviews alone caused the increase.
- The score change was observed in one class, but the cause has not been established.
- 学校はどの要因がその差を説明するのか判断できなかった。
独自長文2|新しい公園標識と道案内の質問
A park installed clearer direction signs near the north gate. During the following week, staff answered fewer questions about how to reach the lake. This seemed encouraging, but rain also kept many visitors away on several days. The office did not count how many people entered the gate before or after the signs were installed. A lower total number of questions could reflect clearer signs, fewer visitors, or both. The park manager recommended recording questions per visitor during comparable weather conditions before claiming that the signs had improved navigation for everyone.
- What decreased after the new signs appeared?
- The number of park gates
- The number of staff direction questions
- The number of signs
- The lake’s size
- What other factor may explain the difference?
- Longer school lessons
- A changed ticket price
- Rain reducing visitor numbers
- A new bridge opening
- What measure is recommended?
- Questions per visitor under comparable weather
- Only total rain in a year
- The price of paper maps
- The number of printed signs
- 実際の変化と、ほかに変わった条件を英語で整理する。
- 誤った断定を修正する:New signs certainly reduced the need for help among every visitor.
- 英文を訳す:A lower total number of questions could reflect clearer signs, fewer visitors, or both.
本文全文和訳・6課題の正答と詳しい理由
【全文和訳】公園は北門近くの道案内標識を改良し、翌週は湖への道順の質問件数が減った。しかし雨で来訪者が減った日もあり、設置前後の来場者数は記録していなかった。質問総数の減少は標識の改善、来訪者減少、またはその両方かもしれない。管理者は同じ天候条件で来訪者当たりの質問件数を測ることを勧めた。
- B:The number of staff direction questions。fewer direction questions।
- C:Rain reducing visitor numbers。rain fewer visitors।
- A:Questions per visitor under comparable weather。questions per visitor comparable weather।
- 観測:Staff answered fewer direction questions in the later week.
【別条件】Rain may have reduced the number of visitors.
【判断の限界】Without visitor counts, fewer questions cannot be attributed entirely to clearer signs.
- The total number of questions fell, but the number of visitors and the weather also matter.
- 質問総数の減少は、標識が分かりやすくなったこと、来訪者が減ったこと、またはその両方を反映している可能性がある。
独自長文3|菜園の雨水タンクと水道水の減少
A school garden began using a small rainwater collection tank in May. During June, staff measured less tap water use than in April. Some club members said the tank had saved all the difference. However, June had more rainy days, and fewer plants were being watered. The team had not recorded comparable daily amounts of water used per plant. A teacher explained that the tank might have helped, but the changes in rainfall and plant numbers also mattered. The club decided to keep detailed records before estimating the tank’s separate contribution.
- When did the garden begin using a tank?
- April
- May
- June
- July
- Which conditions differed between April and June?
- Only the room temperature
- Only the label design
- Rainfall and number of plants
- The museum opening time
- What is the most justified conclusion?
- The tank may have helped, but its separate effect is uncertain
- The tank caused every change
- The tank has no value
- All gardens can save the same amount
- 実際の変化と、ほかに変わった条件を英語で整理する。
- 誤った断定を修正する:Every liter saved was proven to come from the new tank.
- 英文を訳す:The changes in rainfall and plant numbers also mattered.
本文全文和訳・6課題の正答と詳しい理由
【全文和訳】学校菜園は5月に雨水タンクの利用を始め、6月は4月より水道水使用量が減った。部員の一部は減少がすべてタンクのおかげと述べたが、6月は雨が多く水やりする植物数も減っていた。植物当たりの使用量は同条件で記録されていない。教師はタンクの効果の可能性を認めつつ、雨量と植物数も関係すると説明した。
- B:May。started in May।
- C:Rainfall and number of plants。rain and plants differ।
- A:The tank may have helped, but its separate effect is uncertain。separate contribution unmeasured।
- 観測:Tap-water use was lower in June than in April.
【別条件】Rainfall and the number of plants changed.
【判断の限界】The tank’s contribution cannot be isolated from the available records.
- Several factors changed, so the tank’s independent effect remains unknown.
- 雨量と植物数の変化も関係していた。
独自長文4|博物館の短い説明と理解度
A museum replaced several long exhibit captions with short English summaries during a busy holiday week. More visitors completed a short feedback form than during an earlier ordinary week, and many respondents rated the summaries positively. However, visitor traffic was much higher during the holiday, the response forms were voluntary, and nobody was tested on historical understanding. The curator said that favorable opinions were useful for improving the labels, but they did not demonstrate that visitors learned more history. The museum planned to test understanding with comparable visitor groups before changing all of its exhibits.
- What happened during the holiday week?
- The museum closed
- Short summaries replaced some long captions
- All exhibits were removed
- The survey was mandatory
- What has NOT been measured?
- Feedback responses
- Visitor traffic
- Historical understanding
- Number of holiday visitors
- What does positive feedback establish?
- Some respondents liked the summaries, not that learning improved
- All visitors understood everything
- Learning gains were proved
- Visitor numbers were identical
- 実際の変化と、ほかに変わった条件を英語で整理する。
- 誤った断定を修正する:The museum proved the shorter captions increased historical understanding.
- 英文を訳す:They did not demonstrate that visitors learned more history.
本文全文和訳・6課題の正答と詳しい理由
【全文和訳】博物館は混雑する祝日週に長い展示説明の一部を短い英語要約に置換した。通常週より多くの来訪者が任意の感想用紙に答え、好意的な評価も多かった。しかし祝日週は来訪者数が多く、回答は任意で歴史理解のテストもない。学芸員は好評が参考になるものの理解の向上の証拠ではないと説明し、同条件の来訪者群で理解度を調べる予定。
- B:Short summaries replaced some long captions。captions replaced some।
- C:Historical understanding。no test of historical understanding।
- A:Some respondents liked the summaries, not that learning improved。opinions not learning measure।
- 観測:More voluntary forms were completed and many responses were favorable.
【別条件】The holiday attracted more visitors and the voluntary sample may differ.
【判断の限界】No test measured whether visitors understood more history.
- Positive feedback is not direct evidence of better historical understanding.
- それらは来訪者が歴史をより多く学んだことを証明しなかった。
失点を防ぐ復習
観測結果が良くても、proved / guaranteed / because of the new method aloneなど強い言い方に変える前に、比較条件がそろっているか確認します。may have helpedなら可能性にとどめます。
FAQ
Q. 同時に変化したら原因と言えますか?
必ずしも言えません。別の条件が変わった可能性があり、本文の調査方法を確認する必要があります。
Q. 意見が好評なら学習効果が証明されますか?
満足度と知識理解は別の測定対象です。理解度の測定がなければ結果を創作しません。
関連教材
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参考にした公式情報
英検協会|準2級プラス試験内容。独自4長文24課題と和訳・解説は慶英会制作です。

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慶英会 塾長|慶應義塾大学卒・英検1級。中高一貫校の学校英語・NEW TREASURE・英検対策を専門としています。塾長の経歴・指導方針を確認する
