Question: I applied for a position, and the company got back to me with an interview invitation. I accepted, the interview has been scheduled, and the time confirmed. Following this, I had a conversation with my mother who brought up a consideration about the job that didn't previously occur to me (it's location is less than ideal, if you're curious). I don't want the job anymore, but should I cancel? Is going ahead with the interview unethical, as it disrespects the interviewer's time? But I also don't want the cancellation to be a "black spot" on my record. 

Another consideration is that another company sent an interview invitation for the same time, but my main concerns are the ethics and my professional reputation.

Answer: 
Yes. If you are no longer interested in or available for a job, you should cancel the interview in advance. You are not offending the employer in any way.
Why is the location not ideal? Do you really not want the job, or would you want the kind of work if it was located somewhere else? Do you have plenty of other offers or no urgent need to be employed? The answers to those might change this answer, but it might be too early to rule out the job completely.

* "location not ideal" - you will be unlikely to find a job where everything is "ideal", and will have to compromise something. Why not location?
	+ If you do find a job where everything is "ideal", it will be more desirable, competition for it will be stronger; your previous questions say you have no work experience at all and that puts you in a difficult place when it comes to picking and choosing an ideal job - a "less than ideal job" is often better than "no job". Depends on your situation, of course.
* If the "not ideal location" is something every candidate would tend to dislike (e.g. by a busy airport and therefore noisy, or in a place with no local parking), then the company might know this and have to offer more to compensate for it and attract good candidates.
	+ Or if they don't offer more, you could try and negotiate something because of it.
* If they are a bigger company they might have multiple offices, you could find out - if so, ask if they have similar openings at any other locations. They have your name on record and have shown a spark of interest in you, that might get you a similar interview with them, but somewhere else.
* If you go to the interview and are offered the job, you then have (a) a fallback job offer in case other interviews don't go well, (b) a genuine offer you can use when interviewing elsewhere to bargain with ("can you match this offer?"), and (c) a genuine offer which gives you a sense of grounding, you can at least get an offer for a job at that level.
* If the job still has some of its attraction, consider how long you could put up with the location - in order to gain (experience, references, money, etc) - or what you could learn by dealing with the location before moving on.
* The interview might completely change your view on the company or the people. After all, they all manage to work there, so can it really be that bad? Maybe it's not as (noisy, smelly, inconvenient, rough, run-down, difficult to get to) as you expect. Something might make you want the job a lot - and be willing to put up with the location problem - or it might make you not want the job for a dozen other reasons (management practices, other employees, lack of company direction, job is not as advertized).

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> Is going ahead with the interview unethical, as it disrespects the interviewer's time?
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If there is absolutely no way you could be convinced to take the job, then it's a bit unethical for you to take their time for practice, and it's probably better for your reputation if you politely decline than if you turn up and half-ass it or no-show.

But can you really decide with that much certainty, without going to see?