Before seeing a family for the first time, and before, during and after subsequent sessions, the key workers formulate and test working hypotheses. These are preliminary attempts to explain the YP's presenting symptoms in terms of the contexts within which they occur. As more information emerges during the course of therapy, they develop to include all the significant participants and known events and relationships in an interactive pattern that offers both an explanation and possible solutions.

Reasons for making hypothesizing an overt and formal part of the key worker’s role.

1. Firstly, it openly acknowledges the worker's assumptions, prejudices, values and ‘hunches’.
2. Secondly, hypothesizing allows key workers to keep track of their organizing ideas, which can then be viewed and modified in the light of the feedback from the family.
3. In this way the continuous formulation (and refutation) of hypotheses keeps the key workers alert to the active part they are playing in the shaping of the therapeutic reality. The key worker’s hypothesizing, resulting questions and other actions are part of what elicits the particular account the family will tell.

Working guidelines

Hypotheses are working guidelines for organizing the KW's work; thus two or three hypotheses are being entertained simultaneously to guard against the temptation to regard a hypothesis as a factual statement. In this way the KW's interest and curiosity will be kept alive, thereby warding off excessive certainty as well as reducing the risk of engaging in stereotyped and routine work. The following are generic hypotheses which have to be amplified in the light of unique data of the specific family. Many of these hypotheses are overlapping.

Hypotheses address:

1. The social/cultural contexts (the social and gender factors that may precipitate and maintain the presenting problems).
2. The family context (predictable life cycle issues, e.g. adolescence, birth of child, retirement; unexpected life cycle issues, e.g. sudden death, chronic illness; impact of external events, e.g. redundancy.
3. The 'function' the presenting problem has: e.g.
1. 'glue' for family relationships
2. 'punishment for past sins'
3. regulating distance between family members
4. protecting family members
5. controlling family members
6. keeping family of origin involved
7. giving a job to seemingly 'retired' parent(s)

Mentalizing associations with hypothesizing

Hypothesising tends to be tentative in style (see The Therapist's Mentalizing Stance) so that it can invite alternative views or elaborations from family members. An example of hypothesising would be

‘We were wondering in what way A’s mother’s recent hospital admission had affected everyone in the family? Is it possible that it affected A differently from others?’

Or:

‘we wondered who in the family tends to try to make things better if there has been a argument between Dad and the oldest son? Is this something that A tries to do?’