Student Assignments, Missed Deadlines and the Planning Fallacy

The tendency to put off, delay or postpone doing a task is a very common feature of student life, especially when it comes to submitting assignments. This tendency to put off things is known as procrastination, and when it comes to submitting assignments, no matter the length of time available to do an assignment, only a few students submit well before the deadline. The majority tend to submit on or close to the deadline, and a significant few miss the deadline altogether. Those who submit well before the deadline tend to spread out their work over the available period. In contrast, those submitting close to the deadline, or after the deadline, tend to start their assignments with only a few days to go. In fact, it is not uncommon for students to work throughout the entire night prior to the deadline, and to miss classes in the days leading up to the deadline.

Procastination and its consquences

Apart from disrupting other academic activities around the deadline period, the tendency for students to procrastinate has a number of other consequences. First, for the students involved, it can be highly stressful, and has potential health implications. Second, it is likely that in the rush to meet the deadline, stressed-out students may produce low quality assignments, leading to low academic grades. Third, there is a high possibility that students can be overwhelmed by the amount of work they have to do in a very short time, and as a result they may end up not submitting at all.  In fact, from my experience, persistent non-submission of coursework is generally a strong indicator for student non-progression.

According to Pychyl and his colleagues [2000], procrastination is viewed mainly as a time management problem. This view suggests that people who habitually procrastinate have problems with, or are biased, in their time estimation. For example, most people have a tendency of giving lower time estimates for how long it takes to complete tasks. This tendency still persists even when the people concerned have been involved in similar tasks which ended up taking longer than the time they had initially anticipated. This doesn’t apply to students alone, but to professionals as well. For instance, it is a fact of life that IT projects habitually overrun and often exceed budget estimates. Kahneman and Tversky [1977] have coined the term “planning fallacy” to refer to this tendency to make optimistic estimates of task completion despite the fact that most similar tasks have been completed later than anticipated.

Research on the planning fallacy

Researchers working on planning fallacy have observed that people tend to overestimate how much they can accomplish in a given period of time, and they continue doing so even when they know that the estimates that they made for previous tasks have been wrong [Buehler, Griffin & Ross, 1994]. This applies to both novices and experts, and, in our case, to both students and engineers. This suggests that when we estimate the time we will take to accomplish a task, say an assignment, we often don’t take into consideration past experience, or the experiences of others on similar tasks. As Kahneman and Tversky [1977] suggest, we tend to focus exclusively on the specific aspects of the problem at hand, and neglect to take into account any outside information that may affect the task. For example, when deciding when to start an assignment, we may focus only on how difficult the assignment questions are, and whether the solutions can be found in the lecture notes or we need to go to the library. We don’t take into consideration such things as the possibility that we may fall ill, or that some event may occur that will prevent us from fulfilling our tasks. In short, we don’t put in place any contingency planning.

 However, Buehler and colleagues observed that the planning fallacy vanishes when individuals are asked to forecast other people’s task completions. For example, students can accurately predict whether or not their colleagues will be able to submit on time, and, more ominously for academics, students are often able to accurately predict that Professor So-and-so will not return their assignments by the set deadline.

Why are we accurate at predicting other people’s task completions and not our own? One suggestion is that whilst we can accurately perceive another individual as a procrastinator, when it comes to us, we generally view ourselves as victims of circumstances. Another suggestion is that we are so certain of ourselves and our capabilities that we believe we don’t need any additional information when making decisions about ourselves. On the contrary, we are often aware of the lack of complete knowledge that we have about our colleagues, so to address this we often seek out additional information before we make a decision on their time completion [Buehler, Griffin & Ross, 1994].

How can we resolve the planning fallacy problem?

Kahneman and Tversky [1977] suggest that the planning fallacy is intrinsic to individuals to the extent that we often become compellingly attracted to our erroneous estimates even when we are fully aware that they can be wrong. We can therefore only resolve the planning fallacy by letting our beliefs be guided by “a critical and reflective assessment of reality, rather than our immediate impressions, however compelling these may be” [Kahneman & Tversky, 1977]. However, carrying out critical and reflective assessment of your own behaviour and capabilities is easier said than done.

A better approach is to draw on the findings by Buehler and his colleagues and find someone else to analyse your behaviour and capabilities and to give you time estimates on the tasks you are working on. This fits in with our modern ideas that learning is not an individualistic process, but a team process [See my blog entitled Excelling in Engineering School: Collaborate – Being smart is not enough]. To be more effective in your academic studies, you need to work with colleagues, and to take advice from them. Working with colleagues and listening to their advice, no matter how much we may dislike it, will make us better students. And this includes accepting the advice that we are not super heroes when it comes to doing assignments, but, just as any other student, we need to set aside more time than we think we do.


Buehler, R., Griffin, D., & Ross, M. (1994). Exploring the” planning fallacy”: Why people underestimate their task completion times. Journal of personality and social psychology67(3), 366.

Kahneman, D., & Tversky, A. (1977). Intuitive prediction: Biases and corrective procedures. Decisions and Designs Inc., Harvard University.

Pychyl, T. A., Morin, R. W., & Salmon, B. R. (2000). Procrastination and the planning fallacy: An examination of the study habits of university students. Journal of Social Behavior and Personality15(5), 135.

5 thoughts on “Student Assignments, Missed Deadlines and the Planning Fallacy

    • Thanks for your kind comments on my blog. I would be very happy to exchange insights and ideas on this topics since it is of great importance to a lot of students.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s