Hi Emely, I would advise to sacrifice space and add the fourth radio button with a clear label explaining the meaning of the null option. Unselecting a radio button may be learnable, but due to conventions it is not intuitive.
In products it is often possible to unselect by pushing one of the unselected buttons half way. I doubt this behavior is by (interaction) design. It might be just a side effect of the mechanism. - Yohan. ________________________________________________________________ Welcome to the Interaction Design Association (IxDA)! To post to this list ....... [email protected] Unsubscribe ................ http://www.ixda.org/unsubscribe List Guidelines ............ http://www.ixda.org/guidelines List Help .................. http://www.ixda.org/help
