 0, len = linkElements.length; i < len; i++) {
    var e = linkElements[i];
    if(e.innerHTML === correctText) {
      d3.select(e).on('click', function(){ buttonState = 1.0; })
    } else {
      d3.select(e).on('click', function(){ buttonState = -1.0; })
    }
  }

  var linkState = -1.0;
  var correct_text = core.sample(elements).html();  
  console.log([correct_text, elements.length]);
  for(var i = 0, len = elements.length; i < len; i++) {
    var e = elements[i];    
    console.log([e.html(), correc