The decision to research in the first place is 'value laden' - someone has to decide that the research is worth spending money on. Some say that research which the state or business want to see is most likely to get funding. Marxists believe that research is mainly produced from ruling class interests and consequently sociology is been bought.
Its difficult to completely avoid bias and interview effects..e.g. the researcher has to interpret the participants responses (could be bias..even accidental)..the interviewer can unknowingly give off signals or ask questions that lead the respondent towards certain answers.
Questionnaires - e.g. the use of lead in questions...which may lead the respondent to a particular answer.
Some Marxists and Feminists deliberately choose research that gives and end result that they approve of. They believe that sociology should make value judgements about society and suggest ways it could be better.
ALSO..i think you could include things like...
subjective and qualatative approaches being more value laden, as they focus more on the individuals reactions, leading to interpretations rather than objectivity. E.g. theory like social action theory and methods like participant observation, unstructured interviews etc.. where the researcher is more involved in the studies.
ALSO...id include the opposite side..
like stuctural theories and how objective methods such as questionnaires and reseach resulting in statistics will often be more value free ..etc.
ive probably missed quite a bit out that you could use..so if any1 can tell me more then plz do =)