Make three justified recommendations for improving the validity of the marketing research

That depends somewhat on the quality of the market research as it stands, but three things always worth trying are: Make sure you know your target market (No good knowing what people who aren't going to buy or want your product think); ask as many people in your target market as possible (the more people you ask, the more reflective your survey is going to be of the true market opinion); Make sure the survey questions are not leading (in the sense that you should always ask "What do you think of this?" rather than "Do you think this is a good idea?"). I'm sure business studies students will be able to come up with more and better ideas than I have here, so I really wouldn't copy my answer down. But it might give some ideas as to what you can do.

Having done marketing research myself, I would say that the size of the sample is really important. To have real meaning, the sample size should be statistically significant

You should also be very careful in asking open questions - if you lead people with a poorly phrased question you can get skewed results.

Your sampling frame should be objective, ideally random, and - as Jon mentions - of a large enough quota to be statistically significant. Your questions should also avoid being in any way leading to the participant, and nor should the participant feel obliged to answer a certain way because of either your presence or the nature of the research - For example, a market researcher wanting to know if their new soft drink is tasty may be more likely to receive a positive response by offering anyone who participates a £25.00 voucher for their time. As with all research methods, you are seeking the gold standards of reliability, validity and representativeness. If you feel you would benefit from any further discussion of the subject or would like support with the assignment paper, please feel free to get in touch.

I am trying to find out 3 recommendations for a market reseasrch done by Kellogg's re Crunchy Nut bites