These days an overload of information is produced by an exponentially growing number of Internet users, it is a quasi impossible task for an individual to stay up-to-date and keep track of all new and relevant information appearing. Therefore, the evolution to portal websites in which this task is divided over various portal users / members is logical. Also in education, portals can prove their value. Previous research showed that teachers use technology in particular during the preparation of their lessons [1, 2]. The most obvious benefits of using a portal for education are then:

• while searching for specific material: gaining new insights due to different angles from fellow-teachers [2];
• while sharing material: “peer review” ultimately leading to improved learning material [3-5].

User acceptance is the top critical success factor for portal success [6]. To study a user’s technology acceptance, several models were developed building on base social psychology and sociology theories. The most common operationalizations of user acceptance are attitude (ATT), behavioral intention (BI) and self-reported use. The theoretical framework for this study is a combination of the Technology Acceptance Model (TAM, [7]) and the Theory of Planned Behavior (TPB)[8], two models that extend the Theory of Reasoned Action [9]. This way, our model holds five independent variables:

• perceived usefulness (PU) [7]: the degree to which a person believes that using a particular system would enhance his or her job performance;
• perceived ease of use (EOU) [7]: the degree to which a person believes that using a particular system would be free of effort;
• subjective norms (SN) [8]: norms in the social environment of the person concerning use of the system; 
• perceived behavioral control (PBC) [8]: perceptions of internal and external constraints on behavior;
• attitude: this reflects feelings of favorableness or unfavorableness towards performing a behavior. Attitude acts both as a dependent (TAM) and independent variable (TPB).

The portal under study is KlasCement (www.klascement.net), which is supported by the Flemish Department of Education. Although targeting Dutch-speaking Belgian teachers when founded, everybody can enroll. Meanwhile, a separate Belgian and Dutch version has been developed and the site is accessible in two languages: Dutch and English. At the time of writing, over 64000 active members were registered responsible for more than 17000 contributions.

Research questions:

1. which user profiles - based on userlogs - exist?
2. to what extent explain PU, EOU, ATT, SN and PBC users’ intention to use the portal?
3. to what extent do the different user profiles differ in their acceptance of the portal?
4. to what extent can observed portal use at T2 be predicted by ATT, BI and self-reported use at T1?
5. to what extent can PU, EOU, ATT, SN, PBC, gender, duration of membership and age discriminate between uploaders and non-uploaders? 

To address these questions, information from questionnaires will be paired with user data from log files.

1. Russell, M., et al., Examining teacher technology use: Implications for preservice and inservice teacher preparation. Journal of Teacher Education, 2003. 54(4): p. 297-310. 2. Ottenbreit-Leftwich, A.T., et al., Teacher value beliefs associated with using technology: Addressing professional and student needs. Computers & Education, 2010. 55(3): p. 1321-1335. 3. Lai, H.M. and C.P. Chen, Factors influencing secondary school teachers' adoption of teaching blogs. Computers & Education, 2011. 56(4): p. 948-960. 4. Kankanhalli, A., B.C.Y. Tan, and K.K. Wei, Contributing knowledge to electronic knowledge repositories: An empirical investigation. Mis Quarterly, 2005. 29(1): p. 113-143. 5. Wasko, M.M. and S. Faraj, "It is what one does": why people participate and help others in electronic communities of practice. Journal of Strategic Information Systems, 2000. 9(2-3): p. 155-173. 6. Al-Mudimigh, A.S., Z. Ullah, and T.A. Alsubaie, A framework for portal implementation: A case for Saudi organizations. International Journal of Information Management, DOI:10.1016/j.ijinfomgt.2010.05.001. 7. Davis, F.D., Perceived Usefulness, Perceived Ease of Use, and User Acceptance of Information Technology. Mis Quarterly, 1989. 13(3): p. 319-340. 8. Ajzen, I., The Theory of Planned Behavior. Organizational Behavior and Human Decision Processes, 1991. 50: p. 179-211. 9. Fishbein, M. and I. Ajzen, Belief, Attitude, Intention and Behavior: An Introduction to Theory and Research. 1975, Reading, MA: Addison-Wesley.