01Define the question and the kind of search

Start with one sentence describing the task. “Locate the original paper cited for this statement” is different from “identify all studies meeting a defined review question”. Your log should say which task you attempted so that a targeted lookup is not later mistaken for a comprehensive evidence search.

PRISMA-S provides a detailed reporting framework for searches in systematic reviews, including information sources, exact strategies, restrictions and dates. Those principles are useful for ordinary research notes too, but using a small log does not by itself make a search systematic or complete.PRISMA-S reporting guidance (opens in a new tab)

Choose a consistent place to save the record before searching. A plain document or spreadsheet can work. The important feature is that the fields stay together and the record is retained, not that the tool has a particular brand or template.

02Keep a compact record for each search

Copy the executed query rather than paraphrasing it as “searched peptide literature”. If a search was revised, keep the earlier version and state what changed. Otherwise a later reader cannot tell whether a difference in results came from new literature or a different search.

Use stable record identifiers in the saved output where available. A result count alone cannot tell you which records were retrieved. Conversely, a folder of PDFs without a query record cannot show how that set was selected.

03Save what the database actually searched

PubMed's Search Details show how a query was translated, including automatic term mapping. Its History can be downloaded, but the online history is temporary. Save the exact query and relevant translation details in your own record instead of assuming the browser session will remain available.PubMed search guidance (opens in a new tab)

For an original example, a researcher first searches a short compound name and then adds a sequence-specific term after finding unrelated records. The second query is a separate run with a different purpose. Recording only the final query would hide how the earlier records entered the working set.

04Keep retrieval separate from selection

A paper appearing in the results is not the same as a paper being included in an analysis. Add a separate selection note stating whether the record was retained, excluded, awaiting full text or outside scope. Use a reason that another reader can understand, such as “different molecular entity” or “review used to locate primary studies”.

Do not erase a retrieved record simply because its result is inconvenient. If it is outside the question, record the scope reason. If it is relevant but difficult to interpret, retain that uncertainty. The log is most valuable where the path from search to conclusion could otherwise become invisible.

If the same study appears through several records, note the relationship. A conference abstract and a later paper may describe overlapping work. Keeping both search hits does not mean counting them as independent experiments.

05Make an update understandable

When returning to the question, keep the old log and add the new run. State whether you repeated the same strategy or changed the sources, syntax or restrictions. PRISMA-S specifically distinguishes reporting an unchanged rerun from reporting a modified search strategy.PRISMA-S reporting guidance (opens in a new tab)

A different result count does not automatically show an error. Databases and indexing can change. The record's job is to make the circumstances comparable, not to guarantee that a live search engine will return an identical display forever.