Conducting Experiments Using Opus Professional

Arnoud Plantinga

October 11, 2012

1

Contents

Contents 2

1 Introduction 31.1 What is Opus Professional? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.2 The Purpose of This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.3 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.4 Some Basic Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2 My First Publication 62.1 Creating a Publication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.2 Adding Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72.3 Adding Images . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72.4 Creating Buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82.5 Asking about Gender . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92.6 Asking for Age . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

3 Likert Scales 133.1 Creating a Likert Scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133.2 Several Questions on One Page . . . . . . . . . . . . . . . . . . . . . . . . . . 153.3 Using a Loop to Quickly Create Questions . . . . . . . . . . . . . . . . . . . 16

4 Creating Conditions 18

5 Master Pages 195.1 Using Master Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195.2 Scripts in Master Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

6 Authorware vs. Opus Pro 20

Index 21

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Chapter 1

Introduction

1.1 What is Opus Professional?

Basically, Opus Professional (from here on referred to as Opus) is a program to makeother programs. It is a very versatile program; you could use it to make presentations,educational materials, games, or to conduct experiments (surprise!). You could also makeall these things by using a programming language (i.e., by typing long lines of code), butOpus just makes it a bit easier.

There are other programs that do the same thing. For example, you might be familiar withAuthorware (if you are, check out Chapter 6 for the differences and similarities). Qualtricsis another alternative, although a lot more limited in features. I believe that Opus has anice balance between versatility and learning curve.

1.2 The Purpose of This Manual

You can find lot (perhaps all) that you read in this manual also in the manual Opusprovides (go to Help→ Contents & Index to see it). However, whereas Opus providesmore of a reference manual, this manual will take you step by step through the process ofcreating your program. In addition, it is focused on creating experiments. Nevertheless,the manual Opus provides a very handy reference guide, so I’d advise you to use it to findinfo about particular subjects.

Besides this manual and the Opus manual, another great way to learn how to use Opus isto look at things others have created. This can save you a lot of time trying to reinventthe wheel. A great resource is digitalgrapevine.info, a forum of Opus users where you canfind tutorials, downloads, and questions.

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4 CHAPTER 1. INTRODUCTION

1.3 Overview

In the screenshot of Opus above, there are 4 important areas:

1. Page View: This is where you edit the content of your pages. Here you will addbuttons, text, images, etc.

2. Organiser: This part shows the chapters and pages of your publication.3. Tools toolbar: This toolbar shows the different tools you can use, for example, for

creating text, buttons, images, etc.4. Main toolbar: There are some familiar buttons here, such as for creating, opening,

or saving a file. To the right of those are some important buttons to control yourpublication.

1.4 Some Basic Settings

Before we start using Opus we’re going to have a quick look at some basic settings. Thefollowing settings are the ones I use, you should of course choose the settings according toyour personal taste.

Go to T ools→ Options. There are a lot of different settings here, but I’ll highlight themost important ones. If you’re completely new to the program, I’d advise you to changethem to the recommended settings because this manual will assume that you have.

GeneralIn the General part I have the Default Page Size set to 1024×768, because that’s a resolutionthat most modern computer support. Opus will by default note scale your publication,but automatically draw a black border around it. This is nice, because it will keep the sizeof your text, buttons, and so on constant across computers.

1.4. SOME BASIC SETTINGS 5

Furthermore, in Object Properties I’ve deselected both checkboxes to prevent Opus fromautomatically showing some screens.

SpellingIn the Spelling part I’ve disabled Check spelling as you type, because most of the time I’mnot typing in English.

ViewIn V iew→ General, I’ve enabled Single mouse click in Organizer window will open page viewto save me some mouse clicks. I have disabled Use Notes View because I never use notes, sothis will save me some valuable screen space.

Chapter 2

My First Publication

This chapter will show you how to:

• create a publication,• add images, text, and buttons, and• create questions about gender and age.

2.1 Creating a Publication

Let’s create our first Publication! Go to File→ New→ P ublication or click on this icon:. Now, you should see something like this:

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2.2. ADDING TEXT 7

On the left side in the Organiser, you see a little book with the word Untitled1 next to it.This is your publication, which is now called Untitled1. You can change the title by clickingon Untitled1 twice. Inside your publication there is now one chapter called Chapter_1. Youcan divide your publication in as many chapters as you want, which is handy mostly toget a good overview of your publication.

You create your program in Opus by editing pages, which are a bit like slides of a presen-tation. On the page, which is displayed in the Page View, you will place your text, buttons,and so on. You can get a better view of your page by clicking the arrow next to 100% andselecting Fit.

Inside Pages you will create Objects. Objects can be pieces of text, buttons, images, shapes,etc.

2.2 Adding Text

Now we can add some text to our first page by using the Create Text tool. Click on the icon

and click somewhere on the page where you want to place your text. Now, you canenter any text you want. For example, enter ”Welcome to this experiment!”. When you’reentering text, a toolbar will appear with familiar tools to edit your text, such as font, size,boldface, etc.

To see what the experiment will look like for your participants, you can preview your

publication. You can preview starting with the current page by clicking this button orpressing F5, or you can preview starting at the first page in your publication by clicking

this button or pressing F4.

2.3 Adding Images

Similarly, we can add images by using the Create Image tool. Select the Create Image icon

and click somewhere on the page, or drag to create an image of a certain size. Toselect an image on your computer that you want to use, double click on the new imageobject and click Browse. . . . For example, insert a nice logo to make the welcome page looka bit more official.

There are several options for displaying the picture:

1. Fixed: The picture will retain its original size.

2. Tile: The picture will also retain its original size, and will be shown several timeswhen the area is big enough.

3. Centred: The picture retains its size and is centred in the picture area.

4. Scale to fit: The picture will be scaled to the picture area, while optionally keepingits original aspect ratio (using the Keep Aspect option).

You can use the Transparent option to remove a single-color background from your picture.Finally, the Enable Bilinear Resample option smoothens the picture a bit.

8 CHAPTER 2. MY FIRST PUBLICATION

When you’ve added an image to your publication and you hit the savebutton, Opus will ask you whether you want to "consolidate this publication’sresources". It’s a good idea to press the Yes button, as this will save allthe resources (images, movies, sounds) in your publication into a separatefolder called < Y our P ublication′sname > \Resources. When you copy yourpublication to another computer, make sure to copy this folder as well, sothat you have all the images, movies, and sounds you need.1

2.4 Creating Buttons

To create a button, simply click the Create Button icon and click somewhere on yourpage. You can now label the button, for example, label it Continue. You might have toresize the button a bit in order for the text to fit in.

It’s always a good idea to name your pages and objects. In the organiser paneon the left, you can change the names of your pages and objects by clickingtwice on their names. For example, rename your first page to Introduction.

In order to make clicking this button advance to the next page, we need to add some actionsto it. You can tell Opus what to do by binding a certain trigger (e.g., a left mouse click) to acertain action (e.g., go to the next page). We can add actions by Right−click→ Edit Actionsor by pressing Ctrl +E. When you’re in the actions view, on the left you can see the triggerfor the current object. For a button, the default trigger is Left Mouse Click. This means thatif the participant clicks with his left mouse button on this particular button, the actionwill be executed.

Although the Left Mouse Click trigger for buttons works fine most of the time,I advise you to use only the Left Mouse Down trigger. When using the first,the action is not executed when the participant presses his mouse buttonwhen the cursor is above the button, but releases it somewhere else. However,the button does go down, so the participant doesn’t realize that his responsehas not yet been registered. The Left Mouse Down trigger circumvents thisproblem by immediately executing the action when the participant presseshis mouse button when the cursor is above the button.

Change the trigger to Left Mouse Down by first deleting the Left Mouse Click trigger, andthen selecting T riggers→Mouse→ Lef t Mouse Down. At the moment this trigger doesnot have any actions. We can add an action by clicking the Actions tab on the right, anddouble-clicking on one of the actions. We would like this button to continue to the nextpage, so we double-click Go to Page. Next, you can tell Opus to which page you want thebutton to go, but the default is textitForward (which means the page below this one in theorganiser), so that’s fine for now.

At the moment there is only one page, so we have to add a new page by clicking the New

Page button: . Now you can try your publication again using the Preview Button .

1When you’re frequently working on different computers, it’s a lot easier to use a service like Dropboxto synchronize files across computers.

2.5. ASKING ABOUT GENDER 9

2.5 Asking about Gender

Let’s ask our participant about his/her gender! Rename your second page to Gender,and add two buttons to your second page, and label one of them Male and the otherFemale. Now, in order to save the participant’s gender, we will save the participant’s choicein a variable. First, go to the actions view for the Male button. Now select the actionP rogramming→ V ariables→ SetV ariable:

Now there should be an action added to the Left Mouse Down trigger and you should beat the Set Variable tab. You can now create a new variable by clicking the New. . . button.Type in a name for your new variable (e.g., sex), set the initial value to Number → 0.00,and click OK. Now you’ll see that the Variable box says sex.

When previewing your publication, you can view the value of variables tosee if they change properly. To do this, open the Script Console by clickingV iew→ Script Console. Click on the tab Variable Watch, and add a variableby right clicking in the Script Console and selecting Add Watch, and selectthe variable you want to monitor. When you preview your publication, you’llsee the value of the variable in the Script Console.

Below that box, you can tell Opus which value it should assign to the variable sex. In thiscase, we want Opus to set the variable sex to 1 when the participant clicks Male, so we clickNumber and enter 1 in the box on the right. You can leave the Overwrite current contentbox checked, as we want to replace the default value (0) by a new value (1). Now click OKand follow the same procedure for the Female button, but assign the value 2 instead of 1 tothe variable sex.

When you preview this page, you might notice that when you click one of the buttons, itdoes not stay down. To make the buttons stay down after you’ve clicked them, we have toconvert them to radio buttons. For a group of radio buttons, only one of the buttons can bedown at a time. This means that if the participant first clicks the Male button and thenthe Female button, the Male button will go up again. If you want participants to be able toselect several options, you can convert the buttons to checkboxes.

To set the button type, go to the Properties of one of the buttons either by Rightclick→P roperties or by pressing Ctrl +R. In the Tab Button you can choose for Push Button (thedefault), Checkbox, or Radio Button. Choose Radio Button and do not change the group.When you have several questions with radio buttons on one page, you’ll have to assigneach set of radio buttons to a different group. In this case we have only one question withtwo radio buttons, so we’ll assign them each to group 1. Now do the same for the otherbutton and preview the page. You’ll see that one and only one of the buttons will staydown!

10 CHAPTER 2. MY FIRST PUBLICATION

Displaying the Continue buttonWe should give the participants a way to continue to the next page. A simple way of doingthat is by simply copying and pasting the Continue button we created earlier. Select thebutton in the organiser pane, or go back to the first page and simply click on the buttonon the page view. You’ll see that when you paste the button into your second page, it’ll bein exactly the same position as the button on the first page.

However, we want to prevent that participants continue to the next page without answeringour question! We can do that by telling Opus to hide the button, until the participant hasclicked on one of the buttons:

1. Go to the properties of your button object, and select the General tab. Click thecheckbox Initially hidden. This will make sure that the button is initially not shownon the screen.

2. Close the button properties, and go to the Actions screen of the page. Now add thetrigger Advanced → V ariable Changed. This trigger executes an action wheneverthe value of a certain variable changes while the participant is on this screen.

3. Select the variable sex in the dropdown list.4. Go to the Actions tab and add a Show action. Now you can choose which items you

want the action to show. Click the checkbox next to your Continue button.

Now preview your publication, and you should see that the Continue button is hidden,until you click one of the two buttons!

2.6 Asking for Age

Now that we know our participants’ gender, let’s about their age. We can do that using anInput Box, with which you can ask participants to enter text, numbers, or a combination ofboth.

Create a new page and name it Age. Select the Text Input Box tool and click or dragsomewhere on the page. Now open the properties of the input box and go to the Text Inputtab. There are a lot of options here; I’ll highlight the most important ones for now.

2.6. ASKING FOR AGE 11

In the upper part you can select the variable to which the text the participant enters issaved. You can either select a preexisting variable from the dropdown list, or create a newone.

Always make sure that the variables you use to store input information havean empty initial value, because otherwise the participant will see the initialvalue of the variable in the input box. You can do this by creating a newvariable and selecting the Text option as the initial value.

Click New, and create a new variable named age. Leave the initial value as Text andclick OK. In the Limit Input part we can specify what type of characters participants canenter. Because we are interested in the participant’s age at this point, you can uncheckAllow special characters and symbols and Allow letters. You can also limit the length of theparticipant’s response to 2, so that they can only enter two characters at most. Finally,check the box Auto focus. This will make sure that when partcipants enter the page, theycan immediately start typing in the input box, without having to click the box first.

There are two ways in which we can allow participants to go to the next page; we canshow a Continue button or tell them to press enter. When we use the first method, youshould again only let the button appear when the participant has entered something inthe Input box. Similarly to when we were asking about gender, you can add a Variablechanged trigger, but now for the variable age.

To make Enter go to the next page, we’ll have to add a new trigger to the Input box. Add thetrigger Advanced→ Key P ress. This trigger activates when either a random or a specifickey is pressed. You can set the specific key by clicking on the white box next to SpecificKey = and, in this case, pressing Enter. With the Use Modifiers option you can createcombination such as Control + T , but we’ll leave that unchecked for now.

Now we could simply add a Go to P age < Forward > action. However, we need to makesure that participants have actually entered there age. We can check whether they’ve doneso by using the If action. Just like in any programming language, the If action checkswhether a particular condition is true, and executes the action when it is. Now add theP rogramming→ If action.

Because we have to test the length of the variable age instead of just its value, we’ll haveto use an advanced condition. Select Use advanced condition in the dropdown box belowTest. In the white box below it, enter the following text:

length(age)>1

This code basically tells Opus to execute the action under the If statement only if thelength of the variable age is greater than 1. Now add a Go to P age < Forward > actionunder the If action. Now you should see something like this:

12 CHAPTER 2. MY FIRST PUBLICATION

If you now preview this page, nothing should happen when you press enter after enteringno or only one number, but you should go to the next page when you’ve entered twonumbers.

Chapter 3

Likert Scales

Now that we know our participants gender and age, we can start asking some moreinteresting questions. This chapter will show you how to create Likert scales.

3.1 Creating a Likert Scale

We’re going to ask participants how happy they feel at the moment, on a scale of 1 to7. Create a new page and name it Happiness, for example. Now add a button of about50 × 50 pixels, and label it 1 (you might have to increase the font size a bit). In thebutton’s properties, select Radio Button in the Button tab. Now open the button’s actionview, and add the Left Mouse Down trigger. Add the action P rogramming→ V ariables→Set V ariable. Create a new variable named question1 with an initial value of 0, and underSet this variable to the following, click on Number and enter the number 1 in the field to theright. When the participant now clicks on this button, the variable question1 will be setto 1. The action view should now look like this:

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14 CHAPTER 3. LIKERT SCALES

Now duplicate this button 6 times, either by using Right click→ Duplicate or pressingCtrl +D. Drag the buttons and place them on a line next to each other.

You can easily align objects by using the Alignment toolbar. Open it byclicking V iew→ T oolbars and clicking the checkbox next to Alignment. Youcan now space your 7 buttons evenly across the page by dragging one ofthem to the far right, then selecting all the buttons and clicking the Space

Evenly Across icon . You can centre the buttons horizontally by using

the Align Centres Horizontally tool . If you want to centre the group ofbuttons horizontally and vertically on the page, first group the buttons byselecting them and selecting Right Click → Group → Group Objects or

pressing Ctrl +G. Now click the Align Centres icon .

Use the alignment toolbar often to create more professional lookingpublications.

Now change the labels of the but-tons to 2, 3, 4, etc., and add afew Text Objects to the page to dis-play the question and two anchors.You’re page should now look like thepicture on the right. Now we onlyhave to change each button’s actions,so that when the participant clickson button 2, the value of question1will be set to 2. For each button,open the actions view and changethe Set Variable so that question1 isset to the appropriate value.

Now we have created 7 buttons, each of which sets question1 to a different value. Whydidn’t we give the variable a bit more logical name, like happiness, for example? Imaginethat this question is part of a long list of questions about mood, and is followed byquestions about anger, sadness, etc. Then we would have to copy this page and changethe Set Variable action in every button to change the variable anger instead of happiness!To circumvent this problem, we’ll use question1 as a temporary variable, and save theanswer to the actual variable when participant clicks the Continue button.

Copy the Continue button from a previous page and open its actions view. Add a SetVariable action (make sure it is executed before the Go to Page action!) and create a newvariable happiness with an initial value of 0. Now choose to set this variable to a variable,and select question1 from the dropdown list. This means that, in this case, the variablehappiness will take on whatever value question1 has at that moment.

To reset the value of question1, add another Set Variable action and set the value ofquestion1 to 0. This will make sure that the value of question1 is not automaticallyassigned to other variables in upcoming questions.

3.2. SEVERAL QUESTIONS ON ONE PAGE 15

Displaying the Continue buttonTo display the Continue button only when the participant has clicked on of the 7 Likertscale buttons, go to the actions view of the page, add an Advanced→ V ariable Changedtrigger, and choose the variable question1. Add a Show action and select the Continuebutton.

Now preview the page and try out all the buttons. The Continue button should only appearafter you’ve clicked one of the buttons. You can use the Script Console (see the tip onpage 9 for how to use the Script Console) to check whether the value of question1 changesappropriately when you click the buttons.

Creating More QuestionsIf you want to create more questions, such as a question about anger, simply copy thispage. The only things you need to change are:

• the name of the page (e.g., Anger),

• the question text (e.g., ”How angry do you feel at the moment”)

• the Set Variable action in the Continue button (e.g., anger=question1), and

• the anchors, when necessary.)

3.2 Several Questions on One Page

To create several Likert scale questions on one page, first copy your page with one Likertscale and name it (e.g., Happiness_Anger). Now copy the 7 buttons, the question, and theanchor and move it to a convenient spot on the page. While keeping all of your newlycreated buttons selected, go to their properties and to the Button tab. Change the Group to2. This will make sure that clicking a button from the second question will not influencethe buttons from the first question. Now change all the Set Variable actions to adjustthe value of question2 instead of question1. Change the question and the anchors TextObjects and add a Set Variable action to the Continue button, that sets anger to the value ofquestion2.

In order to make the display button appear only when the participant has answered bothquestions, we need to change the triggers and actions that we’ve attached to the page.Open the actions view for the page. There are different triggers we could use. For example,we could add a trigger V ariable Changed→ question2, checking whether the participanthas answered the last question. However, we can also check whether the participant hasanswered all questions. Add a Left Mouse Click trigger, and then add an If action. SelectUse advanced condition, and enter the following text in the white box:

question1>0 & question2>0

This will check whether both question1 has a value bigger than 0 and question2 has avalue bigger than 0. Then add a Show action to the If action, and set it to show yourContinue button. If you now preview your publication, the Continue button should only

16 CHAPTER 3. LIKERT SCALES

show up when you’ve answered both questions, regardless of the order in which youanswer the questions.

If you want the participant to go to the next page only when they’ve answeredyour questions correctly, simply change the condition of the If action. For ex-ample, if the right answers are 3 and 4, change the code to: “question1==3 &

question==4”(you have to use a two “=” signs because you want to comparevalues, instead of assigning them.)

If you want to create more than two Likert scales on page, simply repeat the same proce-dure using variables question3, question4, and so on.

3.3 Using a Loop to Quickly Create Questions

Using one of the pages with Likert scales we could create a scale by copying the pages,changing the question text in each of them, changing the Set Variable action in the Continuebutton. While this is fine for creating short scales, it could get tiring and chaotic whencreating longer scales. In this part I’ll show you how to loop through the same page severaltimes, changing the question every time the participant visits the page again.

First copy one of your pages with one Likert scale and name the new page to somethinglike Likert Loop. Click twice on your question text to edit it, delete all the text, and thenchoose Right Click→ Insert V ariable. With this tool you can display the value of a certainvariable inside a text. Create a new variable question with an initial empty value.

Now we’ll add a script which changes the question variable every time the participantvisits the page. First we’ll create some new variables. Go to P ublication→ P ublicationP roperties→ V ariables. Here you can see an overview of all the variables in your publica-tion. If you check the Hide system vars checkbox the variables that are included in everypublication by default (such as today’s date) will be hidden, and you’ll see all the variablesyou’ve created. Create the following variables by using the Add button:

Variable Initial valuequestion_num Number (0)question_text Arraymood Array

To cycle through a list of questions we’ll create an array. An array is basically a numberedlist of data. We’ll use question_text to store the different questions we’re going to ask ourparticipants, and we’ll use mood to store the answers they give to the different questions.

Opus has three different sorts of data that can be assigned to variables:numbers, strings and arrays. You can do all kinds of mathematical operations(e.g., addition, multiplication, etc.) on numbers but not on strings. Youcan use arrays by referring to a certain position, e.g. newarray[0] refers tothe first element of the array newarray, whereas newarray[1] refers to thesecond element, and so on.

3.3. USING A LOOP TO QUICKLY CREATE QUESTIONS 17

Add a Script to the page by clicking the Script Object icon . A script object that isattached to a page will immediately execute the code inside it once the page is loaded.Paste the following code inside the script object:

question_text[0] = "How happy do you feel at the moment?"question_text[1] = "How angry do you feel at the moment?"question_text[2] = "How sad do you feel at the moment?"

question=question_text[question_num]

The first three lines create 3 elements in the array question_text. The last line assignsthe value of element with the number equal to question_num to the variable we use todisplay the question.

Now open the Actions view for the Continue button. We’re going to add a big chain ofactions to the Left Mouse Down trigger. First add a script by clicking P rogramming →Script and enter the following text:

mood[question_num]=question1

This way, we save the answers participants give to another array, mood. Every time Opusruns through the loop, a new answer is added to the array at position question_num. Nowadd an P rogramming→ If action and set it to Use advanced condition. Enter the followingtext:

question_num<question_text.length-1

To this If action we’ll add the actions that should be executed when the participant hasnot yet seen all of the questions. The code checks whether the number of questions theparticipant has already seen is still smaller than the total number of questions. Now addthe following actions to the If action:

• P rogramming→ V ariables→ Set V ariable: question1 = 0

• P rogramming→ V ariables→ Add: Add 1 to question_num

• Actions→ Go to P age→< Current P age (Reset) >

When the participant has not seen all questions yet, question1 will be reset, ques-tion_num will be increased by 1, and the current page is reset. The last action makes surethat the variable question is set to a different element of question_text.

Now add a P rogramming → Else action to the If action. This action will be executedwhenever the If action is not. In this case, it will be executed when the participant hasseen all the questions from our list. Add the following actions to the Else action:

• P rogramming→ V ariables→ Set V ariable: question1 = 0

• P rogramming→ V ariables→ Set V ariable: question_num = 0

• Actions→ Go to P age→< Forward >

This will reset both question1 and question_num and continue to the next page.

Chapter 4

Creating Conditions

18

Chapter 5

Master Pages

5.1 Using Master Pages

5.2 Scripts in Master Pages

19

Chapter 6

Authorware vs. Opus Pro

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Index

Buttons, 8

Images, 7Input Box, 10

Likert, 13Loops, 15

Script Console, 9

Text, 7

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