There are many correct answers, for there are many differences between the two. Both fixed battery and process approaches are types of neurological tests. These tests measure several brain functions, including memory, intelligence, and attention. A fixed battery approach tests all functions to each person in a group, regardless of the reason they were referred to examine. This measure is more accurate, for every is accessed.
It is more time consuming because it doesn't focus on the reason why they were referred. A process approach is also known as a flexible battery approach. It is flexible because it gives an array of tests, dependent on why the patient was referred. This method is less accurate and provides space for bias.
A fixed battery approach to testing, such as the halstead-reitan neuropsychological test battery, utilizes a pre-determined set of tests in performing neuropsych assessments. This approach uses the exact same set of tests for each client, regardless of referral question.
The advantages are: Abundance of research supporting such batteries, reliability of the subtests when used together fact that this model is easy to train and administer, and utility of indices of functioning, which explain where the cutoff lies between impaired and not impaired.
This model has several disadvantages: It only yields information about what the client can/cannot do (impaired vs. not impaired), not where in the process the breakdown occurs. It assumes that scores mean the same thing for every client. It also lacks a fluid, study component, and it deprives the assessor of the ability to help/test the clients limits. Finally, because this model is so easily trainable, many people giving it rely on the scores to draw conclusions and lack the background knowledge to correctly interpret and diagnose based on testing.
In contrast, a process approach to testing begins with a core battery in mind and is expanded or modified to suit the individual being tested. The assessor chooses the next step in testing based on what has come out of the tests already given. the strengths of this model: Allows for flexibility, so the assessor can get at why, specifically, errors occur, not just that the patient can or cannot do a task, The patients limits can be tested, so the assessor can gather information useful in treatment planning, allows collection of both qualitative and quantitative information, creates an environment more conducive to rapport building, eliminates tests which are not clinically useful. Disadvantages are: tests were not normed together, so any conclusions drawn from their integration is strictly based on clinical judgment. This process requires stepping away from the standardized test approach, so the reliability and validity of the tests used are decreased. Assumes that tests have a level of difficulty relationship to each other.