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  • © 2018

Time Predictions

Understanding and Avoiding Unrealism in Project Planning and Everyday Life

  • Learn why and when your time predictions will be overoptimistic and how to improve the accuracy of your time predictions
  • Read the first book summarizing what we know about judgment-based time predictions
  • Learn how easy it is to influence other people’s time predictions, and why not to do this

Part of the book series: Simula SpringerBriefs on Computing (SBRIEFSC, volume 5)

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Table of contents (9 chapters)

  1. Front Matter

    Pages i-xii
  2. Introduction

    • Torleif Halkjelsvik, Magne Jørgensen
    Pages 1-3Open Access
  3. How We Predict Time Usage

    • Torleif Halkjelsvik, Magne Jørgensen
    Pages 5-11Open Access
  4. Predictions and the Uncertainty of the Future

    • Torleif Halkjelsvik, Magne Jørgensen
    Pages 13-33Open Access
  5. Overoptimistic Predictions

    • Torleif Halkjelsvik, Magne Jørgensen
    Pages 35-54Open Access
  6. Time Prediction Biases

    • Torleif Halkjelsvik, Magne Jørgensen
    Pages 55-70Open Access
  7. Uncertainty of Time Predictions

    • Torleif Halkjelsvik, Magne Jørgensen
    Pages 71-79Open Access
  8. Time Prediction Methods and Principles

    • Torleif Halkjelsvik, Magne Jørgensen
    Pages 81-102Open Access
  9. Time Predictions: Matching the Method to the Situation

    • Torleif Halkjelsvik, Magne Jørgensen
    Pages 103-107Open Access
  10. How to Obtain Overoptimistic Time Predictions from Others

    • Torleif Halkjelsvik, Magne Jørgensen
    Pages 109-110Open Access

About this book

This book is published open access under a CC BY 4.0 license.



Predicting the time needed to complete a project, task or daily activity can be difficult and people frequently underestimate how long an activity will take. This book sheds light on why and when this happens, what we should do to avoid it and how to give more realistic time predictions. It describes methods for predicting time usage in situations with high uncertainty, explains why two plus two is usually more than four in time prediction contexts, reports on research on time prediction biases, and summarizes the evidence in support of different time prediction methods and principles. Based on a comprehensive review of the research, it is the first book summarizing what we know about judgment-based time predictions.

Large parts of the book are directed toward people wishing to achieve better time predictions in their professional life, such as project managers, graphic designers, architects, engineers, film producers, consultants, software developers, or anyone else in need of realistic time usage predictions. It is also of benefit to those with a general interest in judgment and decision-making or those who want to improve their ability to predict and plan ahead in daily life.


Authors and Affiliations

  • Norwegian Institute of Public Health, Oslo, Norway

    Torleif Halkjelsvik

  • Department of Software Engineering, Simula Research Laboratory, Fornebu, Norway

    Magne Jørgensen

About the authors

Torleif Halkjelsvik: Torleif Halkjelsvik works as a research professor (seniorforsker) at the Norwegian Institute of Public Health in Oslo. His research is in the areas of judgment and decision-making, attitudes and attitude change, motivation and emotion, and addictions.

Torleif Halkjelsvik has a background in social psychology and judgment and decision-making. He is interested in the determinants of people's behaviors and decisions in contexts ranging from project management to addictive behaviors.

Magne Jørgensen: Magne Jørgensen is a chief research scientist at Simula Research Laboratory and a professor of informatics at University of Oslo. His areas of specialization are project management, time and cost predictions, and processes for judgment and decision-making under uncertainty. He received in 2014 the ACM Sigsoft award for most influential paper last ten years for the initial paper on evidence-based software engineering. 

Magne Jørgensen has worked with time predictions as a practitioner  (project manager and effort estimation support) in industrial software development projects, as a researcher over more than fifteen years and as an advisor for software companies.

Bibliographic Information

Buy it now

Buying options

Softcover Book USD 24.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Other ways to access