People sometimes feel uncertain in new situations when they do not know what to expect. This uncertainty develops when people do not have a(n) to guide their perception of the new event.

Schema

Explanation:

People sometimes feel uncertain in new situations when they do not know what to expect. This uncertainty develops when people do not have a schema to guide their perception of the new event.  Schema help in interpreting and organizing new information, they are already existing cognitive frameworks that makes individuals cope or adapt easily to new information, environments or events. When there is no existing schema to an event or new information, individuals find it hard to come to terms with such situations or understand and interpret the new information which could lead to feelings of uncertainty and anxiety.