Media richness theory predicts that managers will choose the mode of communication based on aligning the equivocality of the message to the richness of the medium. In other words, communication channels will be selected based on how communicative they are. However, often other factors, such as the resources available to the communicator, come into play. Daft and Lengel's prediction assumes that managers are most concentrated on task efficiency (that is, achieving the communicative goal as efficiently as possible) and does not take into consideration other factors, such as relationship growth and maintenance. Subsequent researchers have pointed out that attitudes towards a medium may not accurately predict a person's likelihood of using that medium over others, as media usage is not always voluntary. If an organization's norms and resources support one medium, it may be difficult for a manager to choose another form to communicate his or her message.