In the social sciences? If they're reproducing the earlier results with the original data and code, the results should be exactly the same. If they're replicat

In the social sciences? If they're reproducing the earlier results with the original data and code, the results should be exactly the same. If they're replicating with a follow-on study of some kind, it depends on any number of factors, since it's almost impossible to do a follow-on survey-based or lab experiment or use a similar or newer dataset while accounting for and controlling exactly the same set of conditions (this is one of the issues that I've heard used to distinguish between hard and soft sciences). E.g., if paper A has an observation count of 200 (insert your preferred number), a replication study could hand out exactly the same survey to another 200 respondents and get similar results that, nonetheless, fail to exactly replicate the earlier findings (or, over a small number of samples, fail to conform to a normal distribution). This doesn't mean that the original study was "bad science" or that the social sciences in general are "bad", only that we have to temper our expectations and maintain a healthy dose of skepticism.