Observational diaries are a good instrument for observing over a long period of time. Diaries are a useful tool to explore long term concerns that you have. An example is to help identify what triggers certain physical conditions or behavioral pattern. It is an informal method of observation and is considered the oldest method in child development. Traditionally it is used over an extended period of a child’s life. In this technique daily records are made of selected aspects of the child’s growth and development. It is not as inclusive as a narrative description because of the continuous contacts with the child over weeks months and years would prohibit the intense writing load required for the narrative description. The degree of inference required is that the observer must make judgments on weather a behavior is indeed new and weather it legitimately belongs in the topical area that is the focus of the study. The diary description is not a likely method for most observers because of its limited usefulness to most observers. The need for continues and close contact with the child rules out almost everyone but parents and other close members to the family. Teacher seldom has such an extensive relationship with a child.