1. Does this information help you answer your main question or one of your sub-questions?
2. On which aspect of your main and/or sub-questions does this source provide information? Does it provide insight into the context of your research area? Or do you now know more about the expected connections between health and green areas in a neighbourhood and does the information help you draw up your theoretical framework?
3. To what extent does the research area or research units in the source found resemble those in your own research? Example: You are researching urban agriculture in Canada and you find a source about urban agriculture in Uganda. You need to evaluate whether the information you have found is relevant to your central question and should form part of your theoretical framework.
4. To what extent does the context of the research found correspond to your context? You must include that context when interpreting your results. If you are researching citizen participation in the Netherlands and you find a source that deals with citizen participation in Russia, you cannot simply assume that the conclusions drawn in that research also apply to the situation in the Netherlands.
5. How current is the source and when was the research carried out? If you are researching the quality of life in the Kanaleneiland area in Utrecht and you find a source that describes developments in Kanaleneiland in the 1970s, that does not provide you with relevant information about the current situation. You can, however, use it as a source when describing the context and giving an overview of the history of Kanaleneiland.

• Checks carried out by others in advance (e.g. editor, peer review, publisher, search engine). An article in a peer-reviewed journal has already been critically reviewed by other academics and is therefore more reliable than an article in a journal in which no checks are made. Some search engines only show results from peer-reviewed journals while Google Scholar, for example, displays many more results. Be extra critical about the reliability of the source in that case.
• Checks carried out by others afterwards (e.g. book reviews).
• Your own checks (e.g. author, date, target group, justification of the methods used, have sources been referenced?). An article that does not reference sources and in which the research method is not clearly explained is much more difficult to assess. You should be careful when using this type of source.

You will often come across theses written by other students when searching for sources. Master’s theses especially can be found quite easily. Use these theses primarily to get an idea of the topic and to find more literature by reading the bibliography. Do not base your entire theoretical framework on the results of these research projects. The research carried out is often small-scale and it can sometimes be difficult to assess the quality.

You may also find articles in specialist literature publications, such as the journals Rooilijn or Geografie in our field. Rooilijn is a journal which focuses on science and policy in spatial planning. Geografie is published by KNAG and provides information on spatial issues in the Netherlands and abroad through opinion articles, background pieces and debates. Articles in these journals are written for a broader audience and give you a general overview of a specific subject. Consult these journals in the initial phase of your literature review and use them to gather inspiration for search terms, research areas or key people.