Note Previous Page Reliability
If your data's as reliable as this then your research is probably in deep trouble...In simple terms, data can be considered broadly reliable if the same results (or broadly similar) can be gained by different researchers asking the same questions to the same (or broadly similar) people. 

Data reliability, therefore, is concerned with ideas such as:

  • The consistency of the data collected.
  • The precision (or lack of same) with which it is collected.
  • The repeatability ("replication") of the data collection method.