It’s not my intention to give full information or an extensive discussion on every theory. This website is intended to be a starting point and the main difference with other websites is the visual representation of the theory, which I hope will help get to grips with the theory. There are also links it the bottom to get your further research started.

Decision Making Theory

Tiedeman and O’Hara 1963

Key is: the importance of the process of ego development on the process of career development.



First of all it’s important to make clear that this theory doesn’t need to be confused or conflated with Life-is-Career theory, by Miller Tiedeman as they are separate theories, though they are linked in other ways. David Tiedeman and Anna Miller Tiedeman were spouses and colleagues and went on to develop the original model further.

David Tiedeman’s decision making model is based on Erik Erikson’s theory of development (Leong, 2008, p.1658), which is in turn rooted in psychoanalysis and Freud’s work. He saw strong link between ‘ego development’ and ‘career development’ (Leong, 2008, p.1658). In order to give you a bit more background on how this model came to be, let’s have a brief look at Erikson’s theory. You can find out more about this theory on if you are interested. Erikson states that healthy ego development depends on the successful management of crises at each stage of life and whether the individual has a favourable view of themselves in relation to the different life contexts at every stage. Tiedeman argues that this in turn is closely linked to career development and the development of career decision making skills.

Erik Erikson's developmental theory of ego development.

As you look further into Erikson’s theory, you will notice that there is a career perspective to most of these stages, which strongly hints at a developmental theory, similar to especially Super’s theory. However, if you read in between the lines of each stage, I can also recognise hints of constructivism, where at each stage, the child or adults writes their own story or realises their own identity within the context of the stage they are in. I can also strongly see the Freudian approach in the way Erikson sees development as a process of resolving conflict related to the ego.

More specifically, if we for instance look at stage 4 of Erikson’s theory, then when a child in primary school is able to make signs or drawings for an occupation or are able to successfully use pliers they will have a sense of success or inferiority if they are not able to, as Sharf (2002, p.150) illustrates. This not only involves the child’s ego and sense of self, but will also have implication for their career decision making. Within this it’s easy to recognise the development of Tiedeman’s and especially Miller-Tiedeman’s development into Life-is-Career theory and within this the development of the individual within a life-career context. Erikson’s focus is very much focused on success, or lack of success, and the value that the ego takes away from that for it’s development. However, Erikson’s work is not directly linked to career development (Sharf, 2002, p.223).

Tiedeman and O’Hara argue that career development is linked to cognitive development and is a part of this (Leong, 2008, p.1658). They recognise and use each of the 8 stages Erikson proposes and, related to what Miller Tiedeman later theorises, by integrating these 8 stages of ‘life development’, argue life and career are integrated. In the example above, in a study in 1977, Tiedeman stated that many 9 year old children were able to state what they are good at and what they are not good at, though girls were stronger at this than boys. But they found out that adolescents are finding it more difficult to accurately see their capacities (Sharf, 2002, p.178, 179) – in the identity and role confusion stage. Working with adolescents myself, I can only assume what may be behind this result, though the original study was conducted in 1959.

Tiedeman and O’Hara focus on the process of decision making, unlike Dinklage, and recognise two phases: anticipating and adjusting to a choice (Sharf, 1997, p.370). They see the career decision making process as a continuous process of throughout life. Tiedeman and O’Hara divide the anticipation stage of decision making up in 4 stages which are not always sequential nor are they age related. Individuals can also be at different stages simultaneously for different career decisions. They can be a guideline for the career professional working with a client (Sharf, 1997, p.370 – 373):

  • Anticipation or Preoccupation
    • Exploration – individuals may follow leads in an unsystematic way, possibly imagining and fantasising or worrying about their deepest fears.
    • Crystallisation – normally represents stabilisation of thought. Thoughts and ideas are more ordered and up and downsides of choices may occur. Temporary choices may occur as well.
    • Choice – clients may have varying levels of confidence in their choice and choices may vary in complexity. Sometimes there is conscious awareness of choice, sometimes there may not be.
    • Clarification – time gives opportunity to reassess the choice and clarify it. If questioned, the client may return to the exploration stage.

The previous stages lead on to the implementation of, and adjustment to a choice (Sharf, 1997, p.373 – 375). The implementation phase deals with carrying out the decision made in the previous phase:

  • Implementation or accommodation
    • Induction – the client implements their choice.
    • Reformation – the changes the client needs to make to fit in with their new situation, following the choice and implementation.
    • Integration – the stage where the newness wears off and the new situation feels familiar to the client.

How can we use this theory in practice?

Just like other change and decision making theories, Tiedeman’s theory can offer a good framework for your work with clients on a day to day basis.  It can be used as a model to help a client through any change and to help them recognise where they are and why are they feeling the way they do. This will require practise, like other models however. It’s an interesting guiding model and you will hopefully recognise some similarity with some other and later models of decision making, namely Lewin’s model and Prochaska and DiClemente model. Like many change models, it requires some extra reading for those interested and I would recommend having a look at the bibliography at the bottom and suggest trying to get hold of some of the works in there.


However, there has been critique about this being a complex and that the terminology was not as clearly defined as it could be. That is not really represented in the article on this page but echoed in different publications. The theory has influenced others, like Harren, but it has had limited appeal, though lately this has changed somewhat. The original theory has had impact in that it was regarded as one of the first constructivist theories (Tiedeman – IresearchNet, 2016).

  • How do you feel about Tiedeman’s model?
  • How would you use it?
  • Which clients would be it be easy to use with and with which clients would it be more difficult. Is age important when using the theory and the model?
  • As always, have a look at Brown to evaluate this theory.

Useful links:


  • Leong, F.T.L. (2008). Encyclopedia of counselling; Volume 2. Los Angeles: Sage Publications.
  • Tiedeman’s theory – IResearchNet (2016) Psychology. Available at: (Accessed: February 26, 2023).
  • Tiedeman, D.V. and O’Hara, R.P. (1963). Career Development: Choice and Adjustment. In-text citation: (Tiedeman and O’Hara, 1963)
  • Sharf, R.S. (1997). Applying Career Development Theory to Counseling. Wadsworth Publishing Company.
  • Sharf, R. S. (2006). Applying career development theory to counseling (4th ed.). Thomson Brooks/Cole Publishing Co.