Final answer:
In the 1965 voting obstacles study using random digit dialing, researchers were likely to encounter sampling bias, non-response bias, and social desirability bias, affecting the representativeness and accuracy of the findings.
Step-by-step explanation:
In 1965, researchers who used random digit dialing to call people and ask about voting obstacles may have encountered several potential sources of bias. The use of landline phones could lead to a sampling bias, as not all demographic groups were equally likely to have landlines. Non-response bias could occur if those who did not answer the phone differed in important ways from those who did. Social desirability bias might also have influenced the answers given, as respondents could have reported what they thought was the acceptable answer rather than their true feelings. Confirmation bias is less relevant in this context because it pertains to how people interpret information in a way that confirms their existing beliefs, rather than the methodology of collecting information.