Behaviour excess: too much behaviour of a particular type (spitting) Behaviour deficit: too little behaviour of a particular type. Discuss the pros and cons of using a diagnostic based vs. a needs based approach. how child is performing in terms of reasoning, working memory, other iq standards. In order to help ensure accuracy the definitions needs to be: clear: specific when describing, objective: must be observable by 1/5 senses, complete: generate examples and non-example. Recording every instance of a behaviour during a specified time segment. Continuous behaviour is not always accurate, better for when there is a clear beginning and end, then it is easy to count. A specified behaviour is recorded a maximum of once per interval throughout an observation period, regardless of how many times the behaviour might occur during interval and regardless of the duration of the behaviour.