Someone asks me this question: 'How much work is it to fix issue? then I'm trying to determine potential impact.'

My answer is that 'very little work should to be done to fix this issue. And there is no extra effect on the whole system.'

Am I right to use the word 'effect' here or should I use other words to express myself more precisely?


Impact and effect can be used to mean more or less the same thing, but in context they usually do not mean the same.

Actually, if you change has no effect on the system, I would not want you to spend time on it. At the very least, I would hope your change would have an effect: the issue should be fixed!

As for impact, in this case, it refers to a larger-scale, usually negative "effect". In software development, and effect to the system would normally refer to a functional change in how the user perceives the system, whereas the impact of a change could mean several things:

  • The actual amount of work that needs to be done for the change: our impact analysis shows we need to change over 100 classes to implement this change.
  • The proportional part of the system in which the (desired) effect is observable: this small change will have a huge impact on the overall user experience throughout the system.
  • The proportional size of the effect of the change: the performance impact is enormous, the system will grind to a halt!

In these case, I would not use effect. I would use that to describe the functional changes:

  • Even if we change all 100 classes, the only effect will be that users see a different typeface on the OK-buttons.
  • _This is a quick win: we make a small (low impact!) change in one place, and the effect is overwhelming: every user can now select their own personal skin for the application!_
  • This database change is unnecessary; even worse, the effect will be a very slow system for our users.

A software developer myself, when I am confident a change should be made, I will always try to present a large effect and a small impact!


There is little difference between the two words but "effect" is a general term and "impact" tends to indicate something more profound. The words can be used interchangeably in the example you quoted above.


Care should be observed in the interchangeability of Effect/Impact when used as a verb. As noted in OED, Effect (v) is defined as "to make something happen," whereas Impact (v) is defined as "Come into forcible contact with another object." As a visual of the difference, consider the following sentence: “When a train impacts a stranded automobile, the collision effects the condition of the vehicle and its passengers.”

Origin of Impact, per OED, states:

Early 17th century (as a verb in the sense 'press closely, fix firmly'): from Latin impact- 'driven in', from the verb impingere.

Impinge from mid 16th century: The word impinge is from Latin impingere ‘drive something in or at’, from in- ‘into’ and pangere ‘fix, drive’. The word originally meant ‘thrust at forcibly’. Impact (early 17th century) comes from the past form of the same source.

The use of Impact as a verb to indicate greater Effect seems to have come into use in the 1960s. I observed this at that time being used by those who were desperate to strengthen both the effect and impact of their words to defend a weak position or field of study. I was particularly perturbed by those in the field of Education, who should have known better, misusing "Impact" in an attempt to gain validation from the scientific community for their research. I understood their frustration with the dismissiveness afforded their scholarly research, especially from those who viewed study of education as nonscientific. However, it seemed counterproductive for those who should have a proper command of the language to abuse it for egocentric purpose.

As an aside, one might be interested to know that this happened at a time when "baby boomers" flooded public schools, and thus created a desperate need for teachers. As a consequence of this need, many college students who could not survive in any other discipline were able to complete a degree program in Education, which had the least stringent prerequisites. Among this glut of new teachers entering the school systems, many of these graduates were little more than "warm bodies" in the classroom. This, in my humble opinion, sounded the death knell in American public education.

  • This is interesting, but your last paragraph does not address the question and is out of place here: this is a Q&A site that focus specifically on questions and their answers, not a forum where tangential topics can be added to the conversation. – Nathaniel is protesting Oct 5 '15 at 15:55
  • @Nathaniel Thank you for clarification, Nathaniel. Sometimes, I get on a roll to offer edification for those who might be interested. Please know that I did not add the last paragraph as a tangential topic, but rather my personal knowledge as the foundation of the information offered in the previous paragraph regarding origin of misuse. I will follow your lead in the future. – Katherine Oct 5 '15 at 16:34

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