The following code caused me a lot of confusion:

<h:form>

  <h:dataTable value="{accountService.things}" var="thing">

   <h:column>

     <f:facet name="header">Name</f:facet>

       <h:outputText id="name" size="10" required="true" value="{thing.name}">

       </h:outputText>

   </h:column>

                         <h:column>

                              <f:facet name="header">Size</f:facet>

                              <h:outputText id="size" size="10" required="true"

                                   value="{thing.size}">

                              </h:outputText>

                         </h:column>

                         <h:column>

                              <s:link value="Select"

                                   action="{accountService.selectThing(thing)}" />

                         </h:column>

                         <h:column>

                              <h:commandButton value="Select"

                                   action="{accountService.selectThing(thing)}" />

                         </h:column>

                         <h:column>

                              <s:link value="Select (dsm)"

                                   action="{accountService.selectThing()}" />

                         </h:column>

                         <h:column>

                              <h:commandButton value="Select (dsm)"

                                   action="{accountService.selectThing()}" />

                         </h:column>

                    </h:dataTable>

                    <h:commandButton value="Show Choices"

                         action="{accountService.getThings()}" />

               </h:form>