Sampling frame can be explained as a list of people within the target population who can contribute to the research.
For a sample dissertation named above, sampling frame would be an extensive list of UK university students. This is the number of individuals from the sampling frame who will participate in the primary data collection process.
In non-probability sampling, on the other hand, sampling group members are selected on non-random manner, therefore not each population member has a chance to participate in the study.
Non-probability sampling methods include purposive, quota, convenience and snowball sampling methods.
The e-book explains all stages of the research process starting from the selection of the research area to writing personal reflection.
Important elements of dissertations such as research philosophy, research approach, research design, methods of data collection and data analysis are explained in this e-book in simple words. (2003) “Essentials of Marketing Research”, 3rd edition, Prentice Hall  Source: Saunders, M., Lewis, P. The number of respondents you need depends on your survey goals and how confident you want to be in your results.The more confident you want to be, the less of a margin of error you should accept.The following observations need to be taken into account when determining sample size: a) The magnitude of sampling error can be diminished by increasing the sample size.b) There are greater sample size requirements in survey-based studies than in experimental studies.Using a 95% confidence level and ±5% margin of error, if we repeated this survey 100 times under the same conditions, 95 out of 100 times, the response would be somewhere between 50% and 60%.A confidence level tells you how reliable a measure is.When calculating your sample size, you'll use the z-score for your confidence level.The z-score is the number of standard deviations a given proportion is away from the mean.In general, the larger your sample size, the lower the margin of error.The closer your sample is in size to your population, the more representative your results are likely to be.