The E-Primer is written with a reader in mind who is eager to learn, but knows little, if anything, about programming, computer science and the actual implementation of all those wonderful scientific experiments that populate the reading lists of psychologists and cognitive scientists. This is not to say, however, that more experienced readers will not find it instructive, as many chapters also deal with advanced E- Prime and programming skills.

What is E-Prime and what will I learn?

E-Prime® is a software package developed and distributed by Psychology Software Tools, Inc. It is specially designed to facilitate development of custom psychological experiments, and to acquire and analyse data. E-Prime consists of several programs with different functions. In The E- Primer, we will discuss E-Studio, E- Basic, E-Merge, E-Recovery and E-DataAid. We will assume you are using E-Prime 2 or 3, but most of the features we discuss were already introduced in E-Prime 1. When versions differ significantly in operation, we discuss each version separately.

You will learn how to use each of these programs effectively, ultimately in order to implement your very own experiments. First, however, you will learn how to recreate a number of fascinating, famous experiments. We will guide you through this process in an easy-to-follow, step-by-step approach – ‘now click on this button over here’ – using Tutorials. Along the way, we’ll explain the reasoning behind each step and give you tips on good practice in experimental design. Gradually, we will move beyond the narrow confines of ‘click-here-now-click-there’ and ask you to implement simple variations on the experiments you’ve met so far. These form the Exercises at the end of each chapter. Finally, in the Additional Exercises, you will be invited to explore, with minimal guidance, the horizons of E- Prime and how you could use what you’ve learned to implement your own research questions. Always make sure that you save your work, because you may need it in subsequent chapters.

Why should I learn E-Prime?

There are a number of reasons to learn E-Prime. First, many students will become involved in a research project during their studies. This will eventually involve setting up and programming an experiment, which requires good E-Prime programming skills.

Overview of available E-Objects

In this chapter, you will learn

So after the last chapter, you know how to test your long term memory. But chances are that if someone talks about having a ‘good memory’ or a ‘bad memory’, they actually mean their working (or short term) memory. Because short term memory is, well, short, you could set up a challenge with your friend and find out in a relatively short amount of time who has the better memory. After this chapter you will be able to do just that, because you are now going to learn how to program a working memory test. Unlike the previous chapter, we won't be working with complicated lists. Instead we’re going to give you a chance to master E-Prime's programming language, E-Basic (which is essentially an old version of Visual Basic for Applications – the same stuff that runs Excel macros, amongst other things).

This chapter provides a psychologist-friendly introduction to Basic programming by first introducing several important Basic programming concepts such as variables, operators, mathematical functions and string functions. You will also learn how to integrate this programming knowledge into your E-Prime experiments and, finally, how to use it to perfect your experiments down to the minute details. Programming has a bad reputation: “geeky”, “difficult” and “boring” are words that came up in the E-Primer Marketing Department's student focus group. We can't really help the geekiness, but we’ll try to get round the difficulties and boredom, because in the end, some things just can't be done without some Basic programming knowledge. If you read carefully through this chapter, digest the theory and carry out all the examples, the tutorial and the exercises, you will be ready to roll. If you ever get stuck with programming, though, you can always ask someone. A great place to turn for help is the online E-Prime discussion group (http://groups.google.com/group/e-prime/). You can also try posting on the E-Prime support forum(https://support.pstnet.com/hc/en-us/community/topics).

E-Basic in E-Prime

All this dragging objects about is fine and dandy, but it doesn't quite feel like programming, does it? According to PST, the developers of E-Prime, E-Prime doesn't require programming, or “using code”.

In this chapter, you will learn

In this chapter you will learn how to make a visual search experiment (e.g. looking for letters in a string) and how to add annoying sound to this task, in order to investigate how distracting sounds affect attention. As before, we start this chapter by describing the basic elements of the objects and elements used in the experiments (particularly the sound object). Furthermore, we provide a down-toearth explanation of digital audio, bit-depth and sample rate (two terms which are often used but poorly understood). You will find out how to counterbalance blocks, use nested Lists and use a jitter (nice Scrabble word!) to create more advanced experimental designs. In addition, we’ll show you how to add devices to your experiment and you will learn about the Match Desktop Resolution At Runtime option, which is handy for running the same experiment on different PCs. We know you’ll be impatient to get started, so without further ado, let's talk about SoundOut objects and digital audio.

SoundOut objects and digital audio

Psychoacoustics has, sadly, not been as popular a part of undergraduate programmes in Psychology as it was back in the late nineteenth century. Consequently, we know far less about auditory perception than we do about the visual system - A good reason in itself to go ahead and study sound! However, on the negative side, it is also clear that people seem to care less about audition than vision, as is easily demonstrated by comparing an average phone's quality HiDPI display with its abysmal speakers. Psychology labs tend to follow this trend: Sound cards tend to be cheap, and speakers quite often hail from the 90s. Even so, you may still find sound to be pretty useful in many experiments - for example, as a way of presenting feedback (e.g. a sharp, loud beep if the participant reacts incorrectly, or when they finish their experiment and you need to wake up). After you have read the section on sound in this chapter, you should be able to avoid the most common errors, and know the basics about digital audio. As a starter, let's look at how to insert sound in E-Prime.

It has been five years since the first edition of The E-Primer and we remain proud of our work. Soon after, however, Psychology Software Tools updated their E-Prime to version 3 with tons of new features. As it quickly became apparent that the demand for The E-Primer far outstripped our expectation, we decided The E-Primer could do with a fresh and shiny coat of paint as well. We are immensely pleased to announce this second edition achieves that, and much more. The most important new features of E-Prime 3 are now all covered, complete with new exercises and tutorials. We also made many adjustments to the original text in response to suggestions from students and colleagues. Hopefully, they will agree this new edition is much improved, without the humorous style being sacrificed: We remain convinced that programming experiments in E-Prime is great fun and should never become a chore.

We would like to thank Saskia van Dantzig for her contributions to the first edition of the book. This second edition has benefited much from expert feedback from David McFarlane and the people at Psychology Software Tools (David Nicholson, Anthony P. Zuccolotto, and Gretchen Brauch): thank you all for all your time and effort! Finally, we would each like to mention a few people personally:

Michiel Spapé: “I would like to express my appreciation for colleagues who supported and inspired my teaching: Thanks, Manuel Eugster (Aalto University) and Liverpool Hope University gang: Letizia Palumbo, Belen Lopez-Perez, Yue Yue, & Antonio Zuffianò. I wish I could imitate you better!” Rinus Verdonschot: “I would like to thank my colleagues and friends for providing me with inspiration and my participants for taking part in my (occasionally mind-numbing) experiments.”

Henk van Steenbergen: “I would like to thank the technicians at the SOLO department at Leiden University for their help and suggestions for improvements and the students and colleagues in my yearly E-Prime classes for their feedback.”

In this chapter, you will learn

In the previous chapter, you have learned how to present texts, using TextDisplays. In this chapter, you will learn how to use ImageDisplays to present images, Slides to present combinations of images and texts, and FeedbackDisplays to present feedback about the participant's performance. Most experiments consist of multiple trials that are similar in some respects, but different in others (e.g. they display different words, numbers, images, colours or shapes). Rather than having to program each trial separately, you can use Lists that contain your trials. The List specifies which properties (attributes) of the trials are fixed and which vary from trial to trial. The List also specifies how often each trial is repeated and in which order the trials are presented to different participants (for example, sequential or random).

After completing this chapter, you will be able to program experiments such as the famous Stroop task and Simon task. What's more, you will be able to discover the hidden prejudices of your friends, by having them perform the Implicit Association Task that you will create in Tutorial III.

Experimental design in E-Prime

When it comes to programming experiments in E-Prime, it is crucial to define every part of your design to the fullest extent. This is true for psychological reasons – you will want to know beforehand how long you should display ‘Drink Coca-Cola’ in order for your prime to be subliminal; whether ‘teal’ and ‘terracotta’ are proper Stroop names, and so on. But this is obvious. However, the baffling complexity of modern computers easily hides their simple natures: they are not aware of your grand designs.

One of the best ways to approach the task of programming is to start with a good plan. For example, John Ridley Stroop may have said to himself, back in 1935: ‘Reading may be an automatic process that can interfere, or inhibit, other skills, such as naming colours’. To test it, he had to go one step further: ‘If reading and naming interfere with one another, then […] naming the colour in which a word was printed should be slower if the colour of the ink is incompatible with the word that was printed (e.g. ‘blue’ vs. ‘blue’)’.

In this chapter, you will learn

One of the best aspects of E-Prime is that it is so widely used. As you have seen while working through the tutorials, a variety of fields related to psychology can and do make use of the experimental paradigms covered here. A simple RT experiment (Tutorial I) is for the classic chronometrist. The Simon Task (Tutorial II) remains popular in cognitive psychology and neuroscience. The Implicit Association Task (Tutorial III) is widely used in social psychology, for example to investigate the effect of stereotypes. Playing a distracting noise while participants are engaged in various types of tasks with varying workloads (Tutorial V) can have great importance for the industrial and organisational psychologist and the burgeoning field of Human Computer Interaction. Understanding self-control (Tutorial VI) remains a hot topic in social psychology. Memory tests (Tutorials VII and VIII) are prevalent in clinical and cognitive psychology and neuroscience, whilst the Ultimatum game (Tutorial IX) and Cyberball game (Tutorial X) are popular among economists and social psychologist. Questionnaires (Tutorials IV, XII and XIV) are, of course, used in all the various fields across psychology and the mouse tracking test (Tutorial XIII) could be applied in clinical and neuropsychological practice.

Thus, E-Prime is used widely throughout psychological and cognitive science and this brings with it a very nice bonus: a number of hardware manufacturers include packages specifically designed for integrating E-Prime with their equipment. PST themselves sell the SRBOX, which comes with five buttons (‘multi-touch’), five lights (‘penta-lit’), and a microphone input (which provides the voice key functionality); but, most importantly, it has great temporal accuracy. Recently, PST also unveiled the Chronos, a USB follow-up to the SRBOX with some new and useful features. Other manufacturers, such as Tobii (an official partner of PST), BrainProducts and EGI, are also well-versed in E-Prime and often offer support and even custom packages for integrating their equipment in your experiment. In this final chapter, you will learn how to interact with various pieces of equipment from within E- Prime.

The Serial Response Box

The Serial Response Box (SRBOX) comes strongly recommended with an E-Prime licence. This is, of course, only to be expected, since the same people who made E-Prime also sell this handy, but rather ugly, little device.