exactly as you would in ordinary writing. Use the past tense to report what happened in the past: what you did, what someone reported, what happened in an experiment, and so on. Use the present ...

For example, the tense may change between the methods section and the discussion section. The abstract is usually in the past tense due to it showing what has already been studied. Example: “This ...

There is no right way of telling a story. Think about which tense will work in your own writing. Experiment with a paragraph in the present and past tense to see which feels best. It's up to you.

There is no right way of telling a story. Think about which tense will work in your own writing. Experiment with a paragraph in the present and past tense to see which feels best. It's up to you.

What place has style in scientific writing? It all depends ... should be discussed in past tense rather than present tense. This helps distinguish previously published work from the new data ...

(Sentence 2 happens to be in the past tense, but 3 is not; both 2 and 3 are in the passive voice ... Finally, make every effort to avoid the Academic Passive, a particularly nefarious style of writing ...