The TDI® (Type Dynamics Indicator) is an approach to measuring Psychological Type published by Team Focus Limited. Based on Carl Jung's theory of the human psyche, it can be used to promote change and growth in individuals, in their personal lives or to working lives. For this reason, the TDI is popularly used in the field of occupational pscychology or human resources.

There are two versions of the TDI® available. The first looks at what an individuals most natural preferences are in terms of various personality dimensions (the TDI'IS' version.) The TDI® was constructed on the understanding of the '4Selfs' Model. This argues that people can answer a questionnaire from different perspectives and this is encouraged. This model argues that we can behave differently in different situations. Sometimes we respond entirely to our environment e.g. paying for our groceries at the checkout. At other times we may be behaving to fulfill a role e.g. the role of a parent/ manager. Despite these different behavioural reactions, individuals still tend to have a general sense of identity. Howevever this can be further complicated, as we may also have an idea of the person we want to become or an ideal image of who we should be. The TDI® also taps into this component in the IS/WANT version, where the individual scores themselves on the way they 'Want' things to be, along with how they believe it 'is'.

The personality dimensions (dichotomies) measured are Extraversion/Introversion, Sensing/ iNtuition, Thinking/Feeling and Judging/Perceiving which leads to 16 different possible typologies. The result of completing the TDI questionnaire is a 4 character typology which includes 1 letter from each dichotomy. For example an individual with the ENFJ type will have a preference for the Extraversion, iNtuition, Feeling and Judging types.

An early example of a questionnaire inspired by Carl Jung's theory is the Singer Loomis. The theory behind this instrument suggests a dynamic relationship between the preferences. It was argued that there is a hierarchy in the order of preferences out of Sensing/iNtuition/Thinking/Feeling and that one preference would be 'dominant'. However this questionnaire has not been as popular as the MBTI, most probably due to it's complexity. Nevertheless, the MBTI also identifies a dominant preference, however not as directly. The popular MBTI™ (Myers-Briggs Type Indicator) has the same basic format as the TDI, however it has been found that more than 50% of people change aspects of their Type when they complete the MBTI for the second time. The TDI aims to overcome this by asking individuals for the 'most natural preference' as it has a greater understanding of the concept of different selves, and the person we are could be different to the person we want to become.

The TDI is a culmination of many years working in the field of personal, team and relationships development. Carl Jung is one of the major reasons for its development. The second most important influence is Isabelle Briggs Myers. Through her development of the MBTI® she has managed to bring many people into contact with some of Jung’s ideas in a very positive way. However, Jung, Myers and most others in the field of human development recognise that people’s strengths can also become their weaknesses. Ironically, this has happened with the use of the MBTI® which, having simplified Jung’s ideas making it easy to introduce and absorb (its strength), has resulted in widespread use which often over-simplifies and sometimes leads to a superficial and rigid application of Jung’s ideas (its weakness).

Probably the best known of the Jungian constructs pertinent to Psychological Type, this describes two opposing “orientations” – one focusses on the external world and the other focuses on the inner world. The former, which he called Extraversion, involves an orientation towards the environment and is recognised by the focus on the object (i.e. the external, objective, physical and shared world). The latter, which he called Introversion, involves an orientation towards the inner world and is recognised by the focus on the subject (i.e. the internal, subjective, private realm). These can be viewed as where the individual gets their energy from or directions of energy flow – either outwards or inwards.

This describes two opposing ways of receiving information and seeing the world. Jung argued that we not only respond to the same situation differently, but we also interpret the same situation differently. Sensing is the function that receives and records sights, sounds, tastes, smells, and touch as well as such bodily sensations as pain and pleasure. It is an immediate, realistic and empirical function that takes in the details of the world and its events. iNtuition is the function that receives and records less conscious or less tangible information. It tends to see patterns, view things as part of a bigger picture, fills in the gaps but sometimes misses out some of the hard facts and details. This concept is easily understood using a food analogy where there is a pile of ingredients. One may see it as a pile of eggs, flour and sugar(sensing preference) whereas another may see the pile as a potential cake (iNtuition preference).

This describes two opposing ways of dealing with and evaluating information (which may have been experienced or gathered by way of sensing or intuiting). Thinking is the function that judges ‘rightness’ or ‘correctness’. It organises information, judges and reaches decisions through logical deliberations. It is a rational, systematic process that seeks to understand reality through analysis, connection between cause and effect and logical inference. Feeling is the function that judges ‘worth’. It reaches decisions by matching against a set of personal values (which may be conscious or unconscious) evaluating whether something is good or bad, pleasant or unpleasant etc. Jung described Feeling as a rational function in the sense that it is not irrational. For example, to prefer the colour green to the colour blue is simply a different way of evaluating and deciding. Feeling judgements can therefore appear more direct than Thinking judgements; it can manifest itself as a ‘one-step’ process that does not always need to justify itself by explicit logic or reasons.

Uniquely, the TDI® recognises that people can answer the questionnaire with different mindsets. other questionnaires have identified this as a problem, the TDI® recognises these as legitimate expressions of ourselves. It therefore rejects the concept of a ‘modal’ self (which leads to the search for a ‘best fit Type’ and which can lead to certain rigidities) and has replaced it with the concept of a dynamic self – a self that is made up of many parts, which are managed and integrated more or less effectively.

The TDI® is designed to help identify a person's most natural style but recognises that sometimes the way you live and interact in your current circumstances may be different from the way you may want or choose to do things in different circumstances. This is explored in the questionnaire by asking you to base your answers on ‘the way it is’ and also on ‘the way I want’. Between 50 –60 % of people show a difference between their IS and WANT profiles. The reasons for the differences can be various and complicated. However, considering these differences can be an extremely useful way to help understand a persons real needs, motivations and preferences and help them to develop themselves.

1 The Current Circumstances hypothesis: Sometimes a persons IS profile is a response to the environment. In what way are your current circumstances demanding that you adopt a particular style – and is this a style that feels comfortable for you in the longer-term?

2 The Outdated Stereotype hypothesis: Sometimes a persons IS profile is a typical view of oneself, built up over many years. Sometimes this view is out-of-date – a person may have changed or developed but is still using the way you have always described yourself. In what ways do you think you have changed over the years? Is that change a response to the needs of what you do or is that change because you have developed greater awareness of who you are and what you really feel comfortable with?

3 The Historical Baggage hypothesis Sometimes a persons WANT profile is based on a deep seated or long-term wish. It could be the case that from an early age the individual was encouraged to believe that there are ‘better’ ways to behave. For example people can be encouraged to be more sociable or extravert 4 The Inner Core hypothesis: Sometimes a persons WANT profile is an expression of the inner person that is ‘trying to get out’. The TDI proposes that life places demands on us and, to manage these, we adapt and do things which, ultimately are not the most natural and satisfying but seem to be necessary just to ‘survive’.

The IS/WANT differences illustrate how our sense of identity can have many facets. The idea that individuals are just one type is not intended or appropriate according to the TDI tool. Exploring what feels most comfortable - and where, when or why – is seen as useful since people who develop greater understanding are able to make more appropriate choices about how to live their lives. They can be freed from ‘living out their history’ or ‘responding to the demands of the moment.’

The TDI® is a series of questionnaires and different users can choose the version which fits their purpose. The broad categories are as follows:

Training is required for those wishing to use the TDI questionnaire and this training can form part of an internationally recognised qualification in Psychological Type with certification issued by the British Psychological Society (BPS).

The final version of the TDI® was standardised on 1260 people who completed the Is/Want version during 2003 and the first part of 2004. The standardisation sample consisted of two main sub-groups: employed, largely professional people, completing the TDI® for personal and careers development, team-building or training purposes, and a sample of undergraduate and postgraduate students completing the TDI® as part of their personal and careers development.

The internal consistency reliabilities for the four TDI® scales are shown below. The high levels of internal consistency show that although items were selected primarily to ensure a good conceptual coverage of the domain, they form a statistically coherent assessment of the four scales with minimal amounts of measurement error.

Internal consistencies of the TDI® scales IS WANT E-I 0.88 0.81 S-N 0.82 0.72 T-F 0.86 0.81 J-P 0.88 0.79

Evidence for the validity of the TDI® comes from a number of sources, starting with Jung’s model of psychological Type from which the rationale and item development framework were developed. The expert reviews of the items during the early stages of development and subsequent statistical analyses contribute further evidence to the validity of the TDI®. The table below shows the intercorrelations between all TDI® scales, so indicating the extent to which each scale is measuring an independent construct.

The associations between the scales indicate that each is assessing a relatively distinct construct. As would be expected, the highest associations are seen between the IS and WANT scores for each scale, indicating a moderate degree of concordance between respondents’ reports of their IS and WANT preferences. The highest association between other scales is for SN and JP Is, and at 0.44 indicates that the two share just under 20 per cent of common variance.

Intercorrelations between TDI® Is and Want continuous scales EI is SN is TF is JP is EI want SN want TF want SN is -0.03 TF is -0.20 0.15 JP is -0.16 0.44 0.29 EI want 0.54 0.04 -0.17 -0.12 SN want 0.02 0.61 0.08 0.28 -0.01 TF want -0.06 0.12 0.57 0.10 -0.10 0.19 JP want -0.08 0.28 0.18 0.43 -0.05 0.42 0.36

Further validity evidence for the TDI® can be obtained by examining the extent to which the constructs it measures converge with similar constructs assessed by other instruments. The table below shows the percentage agreement between the TDI® and MBTI®. These figures indicate a high degree of agreement between the two instruments but, importantly, that the TDI® IS (i.e. where the mind-set is prepared for “the way it is”) is more closely associated with the MBTI® than the TDI® WANT responses (i.e. where the mind-set is prepared for “the way I want”). They also support the importance of the distinction between IS and WANT responses and that the MBTI® ‘mind set’ focuses respondents more on the “way it is” which gets closer to the concept of the ‘Identity Self’.

Reported on TDI® (Is) as % reporting the same on MBTI® Reported on TDI® (Want) as % reporting the same on MBTI® E-I 91.0% E-I 73.9% S-N 83.8% S-N 75.7% T-F 76.5% T-F 65.7% J-P 84.7% J-P 65.7%