Bogardus developed the concept of social distance to measure the degree of closeness or acceptance we feel toward other groups. While most often used with reference to racial groups social distance refers to closeness between groups of all kinds. Social distance is measured either by direct observation of people interacting or more often by questionnaires in which people are asked what kind of people they would accept in particular relationships.
In these questionnaires a number of groups may be listed and the informants asked to check whether they would accept a member of each group as a neighbor, as a fellow worker as a marriage partner and so on through a series of relationships.
The social distance questionnaires may not accurately measure what people actually would do if a member of another group sought to become a friend or neighbour.The social distance scale is only an attempt to measure one's feeling of unwillingness to associate equally with a group. What a person will actually do in a situation also depends upon the circumstances of the situation.