It is ethical to use deceptive methods in research when the scientific goals of the project can be achieved by non-deceptive methods. nih

In general, it is unethical to be deceptive when doing science, especially if the situation doesn't require it. However, there are some cases where not be deceptive would make gathering data or preforming the experiment much much more difficult. My mind goes to psychology experiments where subjects are told they're conducting a study on something different than what they're told the study is on, so that way the subjects act more like their normal selves and not like they're being studied. It doesn't harm the subjects and makes gathering data much easier and more reliable. The only option for these types of experiments to gather data if they didn't lie to their subjects would be to try to record real world situations where their research is relevant, which would be time consuming, much harder and introduce countless new variables making the actual findings much harder to isolate. So long as no one is harmed and reputations aren't ruined, being deceptive is acceptable so long as the appropriate caution is given and the information gained from being deceptive is valuable.