Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Olle Bälter is active.

Publication


Featured researches published by Olle Bälter.


Epidemiology | 2005

Web-based and mailed questionnaires : A comparison of response rates and compliance

Katarina Bälter; Olle Bälter; Elinor Fondell; Ylva Trolle Lagerros

Background: We assessed response rates and compliance for a printed questionnaire and a Web questionnaire in a Swedish population-based study and explored the influence of adding personalized feedback to the Web questionnaire. Methods: We assigned 875 subjects to 1 of 3 groups: printed questionnaire, plain Web questionnaire, or Web questionnaire with personalized feedback. The questionnaire had 2 parts, first a general section and then a dietary section. Results: The response rate for the general section was 64% for the printed questionnaire, compared with 50% for the Web questionnaire with feedback. For the dietary questionnaire, the rates were reversed, resulting in a total response rate for the dietary questionnaire that did not differ between printed and web questionnaire with feedback. Conclusions: Interactivity in the Web questionnaire increased compliance in completion of the second section of the questionnaire. Web questionnaires can be useful for research purposes in settings in which Internet access is high.


nordic conference on human-computer interaction | 2002

Bifrost inbox organizer: giving users control over the inbox

Olle Bälter; Candace L Sidner

Many email users, especially managers, receive too many email messages to read in the time available to them. The solutions available today often require programming skills on the part of the user to define rules for prioritizing messages or moving messages to folders. We propose a different approach: categorize messages in the inbox with predefined rules that do not require maintenance and are scalable to handle anything from 50 to thousands of messages.


human factors in computing systems | 2000

Keystroke level analysis of email message organization

Olle Bälter

Organization of email messages takes an increasing amount of time for many email users. Research has demonstrated that users develop very different strategies to handle this organization. In this paper, the relationship between the different organization strategies and the time necessary to use a certain strategy is illustrated by a mathematical model based on keystroke-level analysis. The model estimates time usage for archiving and retrieving email messages for individual users. Besides explaining why users develop different strategies to organize email messages, the model can also be used to advise users individually when to start using folders, clean messages, learn the search functionality, and using filters to store messages. Similar models could assist evaluation of different interface designs where the number of items increase with time.


Computer Assisted Language Learning | 2007

Pronunciation feedback from real and virtual language teachers

Olov Engwall; Olle Bälter

The aim of this paper is to summarise how pronunciation feedback on the phoneme level should be given in computer-assisted pronunciation training (CAPT) in order to be effective. The study contains a literature survey of feedback in the language classroom, interviews with language teachers and their students about their attitudes towards pronunciation feedback, and observations of how feedback is given in their classrooms. The study was carried out using focus group meetings, individual semi-structured interviews and classroom observations. The feedback strategies that were advocated and observed in the study on pronunciation feedback from human teachers were implemented in a computer-animated language tutor giving articulation feedback. The virtual tutor was subsequently tested in a user trial and evaluated with a questionnaire. The article proposes several feedback strategies that would improve the pedagogical soundness of CAPT systems.


conference on computers and accessibility | 2005

Wizard-of-Oz test of ARTUR: a computer-based speech training system with articulation correction

Olle Bälter; Olov Engwall; Anne-Marie Öster; Hedvig Kjellström

This study has been performed in order to test the human-machine interface of a computer-based speech training aid named ARTUR with the main feature that it can give suggestions on how to improve articulation. Two user groups were involved: three children aged 9-14 with extensive experience of speech training, and three children aged 6. All children had general language disorders.The study indicates that the present interface is usable without prior training or instructions, even for the younger children, although it needs some improvement to fit illiterate children. The granularity of the mesh that classifies mispronunciations was satisfactory, but can be developed further.


conference on computers and accessibility | 2006

Designing the user interface of the computer-based speech training system ARTUR based on early user tests

Olov Engwall; Olle Bälter; Anne-Marie Öster; Hedvig Kjellström

This study has been performed in order to evaluate a prototype for the human – computer interface of a computer-based speech training aid named ARTUR. The main feature of the aid is that it can give suggestions on how to improve articulations. Two user groups were involved: three children aged 9 – 14 with extensive experience of speech training with therapists and computers, and three children aged 6, with little or no prior experience of computer-based speech training. All children had general language disorders. The study indicates that the present interface is usable without prior training or instructions, even for the younger children, but that more motivational factors should be introduced. The granularity of the mesh that classifies mispronunciations was satisfactory, but the flexibility and level of detail of the feedback should be developed further.


Medicine and Science in Sports and Exercise | 2011

Physical Activity, Stress, and Self-Reported Upper Respiratory Tract Infection

Elinor Fondell; Ylva Trolle Lagerros; Carl Johan Sundberg; Mats Lekander; Olle Bälter; Kenneth J. Rothman; Katarina Bälter

PURPOSE upper respiratory tract infection (URTI) is the most common reason for seeking primary care in many countries. Still, little is known about potential strategies to reduce susceptibility. We investigated the relationships between physical activity level, perceived stress, and incidence of self-reported URTI. METHODS we conducted a population-based prospective cohort study of 1509 Swedish men and women aged 20-60 yr with a follow-up period of 4 months. We used a Web-based questionnaire to assess disease status and lifestyle factors at the start of the study. We assessed physical activity and inactivity as total MET-hours (MET task) per day and perceived stress by the 14-item Perceived Stress Scale. Participants were contacted every 3 wk via e-mail to assess incidence of URTI. They reported a total of 1181 occurrences of URTI. We used Poisson regression models to control for age, sex, and other potential confounding factors. RESULTS we found that high levels of physical activity (≥ 55 MET·h·d) were associated with an 18% reduced risk (incidence rate ratio (IRR) = 0.82, 95% confidence interval (CI) = 0.69-0.98) of self-reporting URTI compared with low levels of physical activity (<45 MET·h·d). This association was stronger among those reporting high levels of stress (IRR = 0.58, 95% CI = 0.43-0.78), especially among men (IRR = 0.37, 95% CI = 0.24-0.59), but absent in the group with low levels of stress. CONCLUSIONS we found that high physical activity was associated with a lower risk of contracting URTI for both men and women. In addition, we found that highly stressed people, particularly men, appear to benefit more from physical activity than those with lower stress levels.


Journal of Medical Internet Research | 2013

Two New Meal- and Web-Based Interactive Food Frequency Questionnaires: Validation of Energy and Macronutrient Intake

Sara Elisabeth Christensen; Elisabeth Möller; Stephanie E. Bonn; Alexander Ploner; Antony Wright; Arvid Sjölander; Olle Bälter; Lauren Lissner; Katarina Bälter

Background Meal-Q and its shorter version, MiniMeal-Q, are 2 new Web-based food frequency questionnaires. Their meal-based and interactive format was designed to promote ease of use and to minimize answering time, desirable improvements in large epidemiological studies. Objective We evaluated the validity of energy and macronutrient intake assessed with Meal-Q and MiniMeal-Q as well as the reproducibility of Meal-Q. Methods Healthy volunteers aged 20-63 years recruited from Stockholm County filled out the 174-item Meal-Q. The questionnaire was compared to 7-day weighed food records (WFR; n=163), for energy and macronutrient intake, and to doubly labeled water (DLW; n=39), for total energy expenditure. In addition, the 126-item MiniMeal-Q was evaluated in a simulated validation using truncated Meal-Q data. We also assessed the answering time and ease of use of both questionnaires. Results Bland-Altman plots showed a varying bias within the intake range for all validity comparisons. Cross-classification of quartiles placed 70%-86% in the same/adjacent quartile with WFR and 77% with DLW. Deattenuated and energy-adjusted Pearson correlation coefficients with the WFR ranged from r=0.33-0.74 for macronutrients and was r=0.18 for energy. Correlations with DLW were r=0.42 for Meal-Q and r=0.38 for MiniMeal-Q. Intraclass correlations for Meal-Q ranged from r=0.57-0.90. Median answering time was 17 minutes for Meal-Q and 7 minutes for MiniMeal-Q, and participants rated both questionnaires as easy to use. Conclusions Meal-Q and MiniMeal-Q are easy to use and have short answering times. The ranking agreement is good for most of the nutrients for both questionnaires and Meal-Q shows fair reproducibility.


HCI 97 Proceedings of HCI on People and Computers XII | 1997

Strategies for Organising Email

Olle Bälter

With the increasing flow of email, strategies for organising email messages become more important. Research describes various strategies used for archiving and retrieving messages. Categorising these strategies is important to identify special needs, problems and solutions for users of each strategy. This study extends earlier categories by grouping users after folder usage and cleaning frequency. Conclusions are that the strategies are affected by the choice of mail tool and number of incoming messages, but no influence by the work task or position could be found. Some advice on interface design to support the different strategies is given.


European Journal of Epidemiology | 2005

Demands on web survey tools for epidemiological research

Olle Bälter; Katarina Bälter

In countries where the Internet access is high, a web-based questionnaire could save time and money compared to printed questionnaires, mainly by eliminating the two steps of transferring answers from printed to a digital data set and manually completing missing and impossible answers. However, many of the features wanted for conducting large epidemiological studies are not available in many web survey systems. Here we describe design issues the investigator needs to be aware of when using web-based questionnaires in epidemiological research.

Collaboration


Dive into the Olle Bälter's collaboration.

Top Co-Authors

Avatar

Björn Hedin

Royal Institute of Technology

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Olov Engwall

Royal Institute of Technology

View shared research outputs
Top Co-Authors

Avatar

Hedvig Kjellström

Royal Institute of Technology

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Anne-Marie Öster

Royal Institute of Technology

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge