Confirmation bias in information seeking under simultaneous vs. sequentialinformation presentation

After having made a preliminary or final decision, people often prefer info rmation that supports their chosen alternative to information that conflict s with their choice. Jonas, Schulz-Hardt, Frey, and Thelen tin press) found that sequential presentation of information leads to an wen stronger prefe rence for supporting information than the traditional form of simultaneous presentation. Their proposed explanation for this effect was that sequentia l presentation induces a focus on the prior decision, thereby increasing co mmitment to this decision. The present experiment was designed to rule out an alternative explanation: Being repeatedly confronted with pieces of info rmation to select from could induce the participants to search for more inf ormation than they consider to be necessary, and because less effort is req uired to process supporting information the additional information requests are predominantly for these supporting pieces of information. To test this alternative explanation, in the present experiment - as in the Jonas et al . (in press) experiments - simultaneous vs. sequential information presenta tion following a preliminary decision was manipulated. In contrast to the f ormer experiments, this time the number of information requests was fixed: participants in both conditions had to choose 8 out of 16 pieces of informa tion. The results show that once again a stronger preference for supporting information arises when the information is presented sequentially compared to simultaneously. The alternative explanation mentioned above could thus be ruled out.