I am writing a study for my second academic degree. As usual it has research questions and objectives. My confusion lies in the tenses for these two. The research questions have been answered and the objectives have been reached because right now, I am writing the fourth and fifth chapters. My question: should I change both tenses into past tense or let them be in present tense just like when they were before I startef writing the last two chapters?
Research questions and objectives are generally timeless; if the research question of interest in Chapter 1 is "How does A affect B?", it may be inappropriate to later change it to "How did A affect B?" after obtaining an answer, as this could change the meaning. If the objective is "to [verb]", then this infinitive form can also remain the same.
However, you have a choice when you're presenting your results:
A is found to affect B through mechanism C.
A was found to affect B through mechanism C.
Both can be acceptable in technical/academic writing. Sometimes it depends on whether you want to give a sense of moving through the process (using the present tense) or looking back on the finding (using the past tense).
In a note called "You can go a long way in the present tense", I describe how the present tense is generally useful as a default for describing the findings of the current study; it often sounds more lively and timeless, and it brings cohesion to the manuscript:
A is found to affect B through mechanism C (as described in Section 2.3). C acts by...
In this way, you can distinguish your current results from prior results surveyed in your literature review (and presumably compared with your new results in the discussion section):
Sheikh et al. (2015) reported that... In the present study, however, we conclude, in contrast, that...
The present tense is also useful for describing a procedure or a line of reasoning that can be repeated by the reader at any time.
However, there are some exceptions, which I discuss with examples in that note. For example, the present perfect and future tenses are occasionally used in certain contexts in the academic literature. In addition, the past tense is appropriate when describing events that will not be repeated. The past tense also sounds natural in a conclusion or summary, as the body of work is now completed:
In this study, we aimed to accomplish D, which was achieved by...
In editing, I sometimes find that authors shift from the present tense to the past tense and back again from paragraph to paragraph when describing substantially similar results. Try not to do this; try to have an overarching guideline for which tense you'll use, and stick with it.