Aresearcher compared the recidivism rates of drug abusers that were given probation with those that were sentenced to prison and discovered that the recidivism rates were highest for those sentenced to prison. what potential error is reflected by this conclusion

The potential error reflected in this research is called “Internal Validity”.

Internal validity is the type of error which refers to the extent to which a causal conclusion based on the study is acceptable or not. Acceptability is evaluated based on the degree to which a study minimizes systematic error or bias. In this case, the researcher only has only one variable to compare, which is either the drug abuser was under probation or sentenced to prison. It cannot be determined if other causes aside from the two has effect to recidivism since the research is limited to this, hence resulting to bias.