Chain search/snowball search/unsystematic search

Unsystematic search

An unsystematic search means that information is searched without a predetermined or structured plan. It is an informal search where you do not follow a specific method or strategy.

Features of an unsystematic search:

• There is no strategy for which sources to use, which keywords to use, or how to combine keywords.
• The search can be very broad and cover many different databases and sources.
• When there is no clear plan, it can be difficult to find the information you are looking for and the search can take longer time.
• It is difficult to document and repeat an unsystematic search, which makes it difficult for others to follow or review the search, which usually is important in academia.
• When a systematic method is missing in an unsystematic search, relevant information can be missed, which probably would have been found with a more structured or systematic search.

Citation search / snowball search

Citation search, sometimes called snowball search, is a search technique where you look at the reference lists in your selected articles to find similar articles. These items may not have been included in your search, making this search a complement. There are two types of citation searches, backward chaining and forward chaining.

Backward & forward chaining

Backward chaining is a way to find previous research in your subject. Look in your selected articles' reference lists to find similar articles written before 'your' article. 

Forward chaining is a way to find more up-to-date research in your topic. Look for citations for your chosen articles to see which researchers have referenced them. This is best suited for articles that are a little bit older as  newer articles not always have been cited so much. Here you can use, among other, Google Scholar and their function Cited by.

Chain search

Chain search is a method of information retrieval where you use reference lists from already found sources to find additional relevant material. It works like a chain where each new source leads you on to more sources. Here's a simple explanation of the process:

1. Find a relevant source. Start with a book, article, or other source that is relevant to your topic.
2. Look through the reference list in that source to find other sources that might be useful.
3. Look for new sources. Find and read the new sources that you identified in the reference list.
4. Repeat the process. Continue to review the reference lists in the new sources to find even more relevant sources.

Chain search is especially useful when you want to gain a deeper understanding of a topic and find relevant and explanatory literature.

Citation search and chain search are effective for finding relevant literature, but chain search can provide a broader picture of how a topic has evolved over time.