Time Predictions: Understanding and Avoiding Unrealism in Project Planning and Everyday Life

time predictions; human judgement; overoptimism; uncertainty; project managemen

Time Predictions: Understanding and Avoiding Unrealism in Project Planning and Everyday Life

time predictions; human judgement; overoptimism; uncertainty; project managemen

Time Predictions

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

Software Process Improvement and Human Judgement Heuristics

This paper exemplifies how better knowledge about human judgement strategies known as heuristics can be used to improve software processes, especially estimation and prediction processes. Human judgement heuristics work well when they exploit a fit between their structure and the structure of the environment in which they are used. This use of environmental fit may lead to amazingly good judgements based on little information and simple computations compared with more formal approaches. Sometimes, however, the heuristics may lead to poor judgements. Knowing more about the strengths and weaknesses of human judgement heuristics we may be able to (1) know when to use formal process improvement approaches and when to use less expensive expert judgements, (2) support the experts in situations where the experts’ judgements strategies are known to perform poorly, (3) improve the formal processes with elements from the experts’ strategies, and (4) train the experts in the use of more optimal judgement strategies. A small-scale experiment was carried out to evaluate the use of the representativeness heuristic in a software development effort estimation context. The results indicate that the actual use of the representativeness heuristic differed very much among the estimators and was not always based on an awareness of fit between the structure of the heuristic and the structure of the environment. Estimation strategies only appropriate in low uncertainty development environments were used in high uncertainty environments. A possible consequence of this finding is that expert estimators should be trained in assessing how well previous software projects predict new software projects, i.e., the uncertainty of the environment, and how this uncertainty should impact the estimation strategy

Assessing Practitioner Beliefs about Software Defect Prediction

Just because software developers say they believe in "X", that does not necessarily mean that "X" is true. As shown here, there exist numerous beliefs listed in the recent Software Engineering literature which are only supported by small portions of the available data. Hence we ask what is the source of this disconnect between beliefs and evidence?. To answer this question we look for evidence for ten beliefs within 300,000+ changes seen in dozens of open-source projects. Some of those beliefs had strong support across all the projects; specifically, "A commit that involves more added and removed lines is more bug-prone" and "Files with fewer lines contributed by their owners (who contribute most changes) are bug-prone". Most of the widely-held beliefs studied are only sporadically supported in the data; i.e. large effects can appear in project data and then disappear in subsequent releases. Such sporadic support explains why developers believe things that were relevant to their prior work, but not necessarily their current work. Our conclusion will be that we need to change the nature of the debate with Software Engineering. Specifically, while it is important to report the effects that hold right now, it is also important to report on what effects change over time.Comment: 9 pages, 3 Figures, 4 Tables, ICSE SEIP 202

Total synthesis of tubastrine and 3-dehydroxy tubastrine by microwave-assisted cross-coupling reactions

The first syntheses of tubastrine and 3-dehydroxy tubastrine are described. The target compounds were prepared in four consecutive steps from commercially available starting materials. The central scaffold was formed by a microwave-assisted C–N cross-coupling reaction between 1,3-bis(tert-butoxycarbonyl)-guanidine and (E)-((4-(2-iodovinyl)-1,2-phenylene)bis(oxy))bis(tert-butyldimethylsilane) and (E)-tert-butyl(4-(2-iodovinyl)phenoxy)–dimethylsilane, respectively. The aryl vinyl iodides were obtained by a Hunsdiecker–Borodin-type reaction of aryl acrylic acids, which were easily available from trans-caffeic acid or trans-p-coumaric acid.acceptedVersio

Helsefremming over kaffekoppen : om innovasjon, institusjonelle logikker og mellomrom : en casestudie

Artikkelen tar for seg et nytt helsefremmende tiltak innen eldreomsorgen i en norsk kommune. Tiltaket er et samarbeid mellom en høgskole, en kommunal enhet og frivillige. Vi forklarer hvorfor det nye tiltaket ikke er blitt institusjonalisert som en innovasjon. Den logikken som legitimerer tiltaket, har stått for svakt i forhold til andre institusjonelle logikker til at noen parter har villet ta på seg ansvaret for tiltaket på mer varig basis.publishedVersio

Combining Data Analytics with Team Feedback to Improve the Estimation Process in Agile Software Development

We apply a mixed research method to improve the user stories estimation process in a German company following agile software development. We combine software project data analytics with elicitation of teams' feedback, identify root causes for wrong estimates and propose an improved version of the estimation process. Three major changes are adopted in the new process: a shorter non numerical scale for story points, an analogy-based estimation process, and retrospectives analyses on the accuracy of previous sprints estimates. The new estimation process is applied on a new project, and an improvement of estimates accuracy from 10% to 45% is observed

Substituted Two- To Five-Ring Polycyclic Aromatic Compounds Are Potent Agonists of Atlantic Cod (Gadus morhua) Aryl Hydrocarbon Receptors Ahr1a and Ahr2a

Polycyclic aromatic hydrocarbons (PAHs) are among the most toxic and bioavailable components found in petroleum and represent a high risk to aquatic organisms. The aryl hydrocarbon receptor (Ahr) is a ligand-activated transcription factor that mediates the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other planar aromatic hydrocarbons, including certain PAHs. Ahr acts as a xenosensor and modulates the transcription of biotransformation genes in vertebrates, such as cytochrome P450 1A (cyp1a). Atlantic cod (Gadus morhua) possesses two Ahr proteins, Ahr1a and Ahr2a, which diverge in their primary structure, tissue-specific expression, ligand affinities, and transactivation profiles. Here, a luciferase reporter gene assay was used to assess the sensitivity of the Atlantic cod Ahrs to 31 polycyclic aromatic compounds (PACs), including two- to five-ring native PAHs, a sulfur-containing heterocyclic PAC, as well as several methylated, methoxylated, and hydroxylated congeners. Notably, most parent compounds, including naphthalene, phenanthrene, and partly, chrysene, did not act as agonists for the Ahrs, while hydroxylated and/or alkylated versions of these PAHs were potent agonists. Importantly, the greater potencies of substituted PAH derivatives and their ubiquitous occurrence in nature emphasize that more knowledge on the toxicity of these environmentally and toxicologically relevant compounds is imperative.publishedVersio

Inflammatory effects of exposure to different stone types used in Norwegian asphalt

During the winter in Scandinavian countries, up to 90% of traffic-related particulate matter (PM) is from non-exhaust emissions sources such as asphalt wear. Measures to reduce urban PM have focused mainly on exhaust emissions, while the contribution from asphalt has received less attention. In vitro studies suggest that the composition of asphalt can affect the inflammatory potential of road dust. Using a whole-body human exposure chamber, we have explored whether different stone materials used in Norwegian asphalt impose different inflammatory reactions in plasma of healthy volunteers. Our results show no acute increases in the inflammatory markers SP-D, P- selectin, or CC16. However, quartz diorite induced an apparent increase in ICAM-1, not seen for rhomb porphyry or placebo dust (lactose). Although this did not reach statistical significance, it resembles previously observed fibrinogen-effects, and may suggest that different types of stone minerals provoke different inflammatory reactions in humans compared to placebo dust.publishedVersio