Browsing by Subject "Judgement"

Now showing 1 - 8 of 8

Open Access
Currency forecasting: an investigation of extrapolative judgement
(Elsevier, 1997) Wilkie-Thomson, M. E.; Önkal-Atay, D.; Pollock, A. C.
This paper aims to explore the potential effects of trend type, noise and forecast horizon on experts' and novices' probabilistic forecasts. The subjects made forecasts over six time horizons from simulated monthly currency series based on a random walk, with zero, constant and stochastic drift, at two noise levels. The difference between the Mean Absolute Probability Score of each participant and an AR(1) model was used to evaluate performance. The results showed that the experts performed better than the novices, although worse than the model except in the case of zero drift series. No clear expertise effects occurred over horizons, albeit subjects' performance relative to the model improved as the horizon increased. Possible explanations are offered and some suggestions for future research are outlined.
Open Access
Evaluating predictive performance of judgemental extrapolations from simulated currency series
(Elsevier, 1999) Pollock, A. C.; Macaulay, A.; Önkal-Atay, D.; Wilkie-Thomson, M. E.
Judgemental forecasting of exchange rates is critical for financial decision-making. Detailed investigations of the potential effects of time-series characteristics on judgemental currency forecasts demand the use of simulated series where the form of the signal and probability distribution of noise are known. The accuracy measures Mean Absolute Error (MAE) and Mean Squared Error (MSE) are frequently applied quantities in assessing judgemental predictive performance on actual exchange rate data. This paper illustrates that, in applying these measures to simulated series with Normally distributed noise, it may be desirable to use their expected values after standardising the noise variance. A method of calculating the expected values for the MAE and MSE is set out, and an application to financial experts' judgemental currency forecasts is presented.
Open Access
Evaluating strategic directional probability predictions of exchange rates
(2010) Pollock, A.C.; Macaulay, A.; Thomson, M.E.; Gönül, M.S.; Önkal, D.
The current paper aims to examine strategic predictions (with forecast horizons greater than six months) via the empirical probability (EP) technique. This technique was proposed initially to examine short-term tactical predictions (with forecast horizons less than three months), as set out in Pollock et al. (2005). The proposed procedure is based on the hypothesis that changes in logarithms of daily exchange rates follow a normal distribution over short horizons (of 10 to 30 days), but longer term forecast evaluation requires consideration of cumulative parameters consistent with changing means and standard deviations arising from primary and secondary trends. It is shown that ex-post EPs can be obtained for any predictive horizon above 30 days (e.g., 180 days) by using a combination of shorter (e.g., 20-day) Student t distributions. The procedure is illustrated using daily Euro/USD series from 4 January 1999 to 29 January 2008 to evaluate a set of Euro/USD directional probability predictions. © 2010 Inderscience Enterprises Ltd.
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İlham veren kadınlar: İlk kadın Danıştay Başkanı Füruzan İkincioğulları'nın gözünden 1994-1998 yılları arası ; Danıştay
(Bilkent University, 2018) Mutlu, İdil Simge; İkincioğulları, Alp; Uysal, Salih Cem; Bingöl, Cem
Bu araştırma projesinde, Türkiye Cumhuriyeti'nin ilk kadın Danıştay Başkanı olan Füruzan İkincioğulları'nın yorumları ışığında, Türkiye Cumhuriyeti'nin 1994-1998 yılları arasındaki siyasi ve hukuki olaylarının değerlendirilmesi hedeflenmiştir. Bu olaylardan 28 şubat Darbe Girişimi üzerinde özellikle durulmuştur. Füruzan İkincioğulları, 1933 yılında doğmuş, zorlu bir eğitim hayatından sonra tetkik hakimi olarak görevine başladığı Danıştay'a 1994'de başkan olup, bu görevi 1998 yılına kadar sürdürmüştür. Bu proje, Füruzan İkincioğulları'nın hayatının ve görüşlerinin tam anlamıyla anlaşılabilmesi ve incelenebilmesi amacıyla; Füruzan İkincioğulları'nın eğitim hayatını, kariyerini, Danıştay macerasını, başkanlık sürecini, bir kadın olarak karşılaştığı zorlukları/kolaylıkları ve kendisinin hukuk ile ilgili görüşlerini ana başlıklar olarak barındırmaktadır. Projenin temel kaynağı olarak Füruzan İkincioğulları ile yapılan röportaj kullanılmıştır. Bunun yanında, Ankara Barosu ve Gazi üniversitsesi gibi çeşitli kurumların dergileri ve dönemin hukuki ve siyasi olaylarına ilişkin kitaplardan da yararlanılmıştır.
Open Access
The influence of trend strength on directional probabilistic currency predictions
(Elsevier, 2003) Thomson, M. E.; Önkal-Atay, D.; Pollock, A. C.; Macaulay, A.
An experiment is reported which compares the judgmental forecasting performance of experts and novices using simulated currency series with differing trend strengths. Analyses of directional probability forecasts reveal: (1) significant effects of trend strength on all aspects of predictive performance being studied, with evidence for the hard-easy effect where overconfidence is exhibited on weak (i.e., more difficult) trends, while underconfidence is shown on strong (i.e., less difficult) trends; (2) lower performance of experts on relative accuracy and profitability measures, reflecting experts' resistance to strong trends; (3) better overall performance on negative trends; and (4) superior performance of composite forecasts. Possible explanations are offered for these results and future research directions are outlined.
Open Access
Judgemental forecasting: a review of progress over the last 25 years
(Elsevier, 2006) Lawrence, M.; Goodwin, P.; O'Connor, M.; Önkal D.
The past 25 years has seen phenomenal growth of interest in judgemental approaches to forecasting and a significant change of attitude on the part of researchers to the role of judgement. While previously judgement was thought to be the enemy of accuracy, today judgement is recognised as an indispensable component of forecasting and much research attention has been directed at understanding and improving its use. Human judgement can be demonstrated to provide a significant benefit to forecasting accuracy but it can also be subject to many biases. Much of the research has been directed at understanding and managing these strengths and weaknesses. An indication of the explosion of research interest in this area can be gauged by the fact that over 200 studies are referenced in this review.
Open Access
Performance evaluation of judgemental directional exchange rate predictions
(Elsevier, 2005) Pollock, A. C.; Macaulay, A.; Thomson, M. E.; Önkal, D.
A procedure is proposed for examining different aspects of performance for judgemental directional probability predictions of exchange rate movements. In particular, a range of new predictive performance measures is identified to highlight specific expressions of strengths and weaknesses in judgemental directional forecasts. Proposed performance qualifiers extend the existing accuracy measures, enabling detailed comparisons of probability forecasts with ex-post empirical probabilities that are derived from changes in the logarithms of the series. This provides a multi-faceted evaluation that is straightforward for practitioners to implement, while affording the flexibility of being used in situations where the time intervals between the predictions have variable lengths. The proposed procedure is illustrated via an application to a set of directional probability exchange rate forecasts for the US Dollar/Swiss Franc from 23/7/96 to 7/12/99 and the findings are discussed.
Open Access
Wisdom of group forecasts: Does role-playing play a role?
(Pergamon Press, 2012) Önkal, D.; Sayım, K. Z.; Lawrence, M.
Forecasting plays a special role in supply chain management with sales forecasts representing one of the key drivers for collaborative planning and decision making in the organisations involved. We review the important role played by judgemental forecasts in this area, focusing on group predictions. Noting the scarcity of research using group forecasts, we present the results of an experiment where consensus forecasts are elicited from structured groups with and without role-playing. Comparisons with groups without any assigned roles show that getting into tailored organisational roles does have a significant effect in the resultant forecasts. In particular, members of the role-playing groups show less agreement with consensus forecasts and display a strong commitment to their assumed roles and scripts. Furthermore, role-playing groups leave a higher percentage of model-based forecasts unadjusted and when they do make an adjustment, it is significantly less than the groups, whose members are not assigned roles. Differences between the role-playing conditions are interpreted as highlighting the importance of role framing on forecast adjustment and group forecasting behaviour. Future research directions are proposed to improve the accuracy and acceptance of group forecasts.