Parents with poor personal experiences of education may identify the researcher with the school and refuse to participate
Some parents may see questions about parental support for their child's education as 'getting at' them or attempting to portray them as bad parents
If the researcher can gain parents' trust, they may be more willing to talk because it gives them the opportunity to speak about their feelings towards school
Parents are not easily contacted, except through school, so the researcher has to depend on the head's cooperation
Another way of contacting parents is through the school's parents association, but the middle class are more likely to get involved in such organisations, which may reduce representativeness
Issues such as truancy or parental support are sensitive, and parents may be defensive about their role, for example exaggerating the support they give
Parents are used to receiving and returning communications from school and may see involvement in the research as a useful aspect of their relationship with the school
Some parents have literacy or language problems or may find it difficult to articulate their feelings