Business Japanese – Difference between “予想・予測”, “推量・推定”

Table of Contents

1. Difference between “予想よそう・予測よそく“, “推量すいりょう・推定すいてい“
2. 予想よそう VS 予測よそく
3. 推量すいりょう VS 推定すいてい
4. Summary
5. Quiz
6. Similar Articles
7. Comment

Q: Could you explain the differences between “予想よそう” and “予測よそく,” as well as “推量すいりょう” and “推定すいてい,” commonly seen in business contexts?

A: The distinction lies in whether they are subjective or objective. Let’s take a closer look at each.

予想よそう VS 予測よそく

Let’s start by looking at the meaning and usage of “予想よそう” and “予測よそく.” These two terms have similar meanings, which might make distinguishing between them a bit difficult. However, broadly speaking, “予想よそう” is subjective, while “予測よそく” is objective.

“予想よそう” refers to predictions or perspectives about the future made by individuals or groups. It can also be based on intuition or the speaker’s experience, and this is perfectly acceptable.


[Examples]
わたしの予想よそうでは、このプロジェクトは成功せいこうすると信しんじています。
I believe that, according to my expectations, this project will be successful.

プロジェクトの計画けいかくは予想よそう通どおりには進すすみませんでした。

The project’s plan did not proceed as expected.
⇒ In the expectation, it was believed that the project would proceed faster or more smoothly, but that was not the case.

This word is often used with expressions like “以上いじょう” (more than) / “以下いか” (less than) and “より（も）” (than). In this case, it expresses that the speaker had predicted or expected something contrary to the actual result.


[Examples]
（もっと遅おそいと思おもっていたのに）予想よそう以上いじょうに仕事しごとが早はやくできました。
(I thought it would take longer, but) the work was completed faster than expected.

（いい結果けっかを期待きたいしていたのに）予想よそう以下いかの結果けっかでした。
(I was expecting good results, but) the outcome was below expectations.

（そんなにうまく行いかないと思おもっていたのに）A社しゃとの企画きかくは予想よそうよりもうまくいきそうです。
(I didn’t think it would go so well, but) the project with Company A seems likely to succeed beyond expectations.

This term is also used to make predictions about changes or outcomes of certain matters based on data or evidence as a foundation.


[Examples]
今後こんご、株価かぶかは上あがると予想よそうされています。

It is predicted that stock prices will rise in the future.
⇒ “Stock prices” are subject to change, and this prediction is based on data and other factors.

明日あしたは高速こうそく道路どうろが非常ひじょうに混雑こんざつすると予想よそうされています。

It is anticipated that highways will be extremely congested tomorrow.
⇒ “The level of traffic congestion” are variable, and this prediction is made based on current conditions and past data.

On the other hand, “予測よそく” refers to making predictions or estimations in advance based on reliable evidence such as data or proof. The foundation for these predictions often comes from “data” or “scientific/statistical” information.

Therefore, compared to “予想よそう,” it is more objective and can be considered an estimation based on solid evidence.


[Examples]
お客きゃく様さまの動向どうこうを予測よそくするために、過去かこのデータを分析ぶんせきすることにしました。
We decided to analyze past data to predict customer trends.

気象きしょう庁ちょうによると、明日あしたはかなりの雨あめが降ふると予測よそくされています。
According to the meteorological agency, significant rainfall is expected tomorrow.

推量すいりょう VS 推定すいてい

Next, let’s explain the difference between “推量すいりょう” and “推定すいてい.” These two terms differ in that “推量すいりょう” is subjective, while “推定すいてい” is objective.

First, “推量すいりょう” refers to making judgments or predictions about things that have not yet happened or are unknown, based on subjective intuition or experience. This typically lacks specific evidence or proof.
It is also often used when the speaker infers the other person’s feelings or thoughts from their facial expressions.

[Examples]
次つぎの企画きかくの成功せいこうを推量すいりょうするには、データが少すくなすぎます。
There is too little data to speculate on the success of the next project.

それはあなたの勝手かってな推量すいりょうですよね。もっとしっかり考かんがえてから意見いけんしてください。
That’s just your arbitrary speculation, isn’t it? Please think more carefully before giving your opinion.

社長しゃちょうの表情ひょうじょうから推量すいりょうするに、冬ふゆのボーナスは減へりそうです。
Judging from the president’s expression, it seems likely that the winter bonus will be reduced.

On the other hand, “推定すいてい” differs from “推量すいりょう” in that it refers to drawing conclusions about unclear matters based on objective facts or materials as evidence.

[Examples]
彼かれの年収ねんしゅうは推定すいていで2000万まん円えんぐらいと言いわれています。
His annual income is estimated to be around 20 million yen.

⇒ His income is inferred based on his job details and profession.

今回こんかいの地震じしんでおよそ1000人ひとが亡なくなったと推定すいていされています。

It is estimated that approximately 1,000 people died in this earthquake.
⇒ While the exact number of fatalities is unknown, an approximate figure has been calculated based on data.

Summary

[予想よそう VS 予測よそく]

• “予想よそう” refers to predictions or perspectives about the future based on subjective considerations. It is also used when changes or outcomes are inferred based on data or evidence.
• “予測よそく” is more objective than “予想よそう” and is used to estimate in advance based on data or evidence.

[推量すいりょう VS 推定すいてい]

• “推量すいりょう” refers to judgments or predictions based on subjective intuition or experience, without specific evidence or proof. It is also used when inferring someone’s feelings or intentions from their facial expressions.
• “推定すいてい” is used to draw conclusions based on objective facts or materials, relying on evidence when something is not clearly understood.

Quiz

Read the following sentence and choose the expression that fits the context from the options provided in the parentheses.

Click on the question to check the answer.

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