In the description design framework, there are state descriptions and responsive descriptions. The state descriptions are available for learners to experience at any time and provides the learner with the current state of the interactive. The responsive descriptions are heard as learners interact with the interactive objects, like buttons, sliders, and draggable objects. And provide information about the relevant changes occurring as the learner interacts. These two categories of information, the current state and relevant changes, when woven together through the learner's interactions, support exploration and tell the story of the interactive. This week, we're taking a deep dive into state descriptions. Learners will typically encounter the state descriptions first when they initially encounter the interactive and begin reading through the content to understand what is there. Once a learner starts interacting with the simulation, they can return to the state descriptions to read any piece of the content at any time. Remember the non-visual reading experience is active. Learners use a screen reader to actively navigate within the text. So state descriptions are both their first introduction and the location of on-demand information. As designers, our goal when designing state descriptions is to set the scene as to what is in the interactive, provide necessary details as learners start their exploration. And provide additional details about objects and relationships. We aim to do this in a way that is always accurate. The description is verifiably true. Equivalent, everything the interactive provides through non-auditory modalities to address the learning goals is also provided through description. Objective, the description describes only information displayed in the simulation without conclusions, inferences, or opinions about what is represented. This allows the learner using the description to connect the dots themselves, just as learners using other modalities in their interactive can do. And essential, description focuses on describing essential information conveyed by the interactive and essential to the interactive experience. For example, we don't need to literally describe all visual details. But we do want to ensure we describe all details conveyed by the visuals that are relevant to the learning goals and enable learners to engage in sense making. As well as any visual details that contribute to the interactive being fun or interesting. And we do all of this in a way that supports and encourages the learner to transition from reading to interacting. It's interacting with objects that make the changes happen and drive the exploration and the story of the interactive forward. A foundation of PhET's design approach is implicit scaffolding, supporting learners to engage in productive pathways of exploration without explicit instruction. Implicit scaffolding of the descriptions is the strategy we use to achieve our design goals. For example, the visual design of PhET simulations implicitly encourages useful interactions through our visual design choices. For example, through the choice of the size, location, and color of objects. Similarly, the words and structures of state descriptions in PhET sims implicitly encourage useful interactions through non-visual design choices. For example, our use of headings, lists, object names, sentence structures, and word choices. For more general information about PhET's implicit scaffolding approach, please see the implicit scaffolding papers listed in the course resources. We rely upon documents and interaction semantics to provide the words and meaningful structures that implicitly scaffold learners. Document semantics, which includes headings, regions, and lists provide the organization laying out of the description. So important relationships between objects, groups, or regions are clear and descriptions are easy to navigate. Document semantics communicate to the learner the relationships and relative importance of objects. We use interaction semantics along with action-oriented object names to communicate interaction points and their function, such as buttons, sliders and checkboxes. To enable learners to easily identify interactive objects and to implicitly guide learners in their transition to interaction. The approaches we use to implicitly scaffold descriptions result in design patterns, which are specific strategies and examples that can be used as a template or starting point when designing descriptions for a new interactive. Throughout this course, we'll introduce you to multiple description design patterns we have developed and utilized in our own design work. We'll help you apply these to your own description designs. Let's take a look at the sim Ohm's law and consider state descriptions for this simulation. So here's Ohm's law. We have an equation voltage V equals current I times resistance R. We have a circuit with batteries and a resistor and two sliders, and one for voltage and one for resistance. We're going to turn the sonification and sound effects off for now so you can hear me talking better. What information would someone new to the simulation need to know to get started? Now imagine someone is in the middle of using the simulation. At a random moment in time, we take a snapshot of the screen. All of the interactive objects are each in a certain state. The visual representations are in a certain state, all frozen in our snapshot. How could you describe the state of the interactive in the snapshot? Now imagine the learner keeps using the interactive. And a few minutes later, again, we take a snapshot. In our second snapshot, all of the interactive objects are in a certain state and the visual representations are in a certain state, but some are different than the first snapshot we took. How can we describe the state of the interactive in the second snapshot? Think about the interactive you've picked to describe. Think about it being used and taking a snapshot at a moment in time, and then in a later moment in time. How could you describe the state of the interactive in each of these snapshots? Let's take a look at the snapshot of Ohm's law. In both of these snapshots, there are some things that remain the same. In both, there is an equation, a circuit, two sliders, and a reset all button. The units of the variables for current, milliamps, voltage, volts, and resistance, ohms, are the same in both snapshots. Not everything is the same, though. There are some things that are different. In one of the snapshots, the current is 9 milliamps, the voltage is 4.5 volts, and the resistance is 500 ohms. And in the equation, the I for current is much smaller than the V for voltage, which is similar in size to the R for resistivity. In the other snapshot, the current is 900 milliamps, the voltage is 9 volts, and the resistance is 10 ohms. There are differences in the circuit as well. The size and number of the batteries in the circuit are different, and the visual display of the resistor in the circuit is different as well. For example, in one snapshot, the resistor has lots of little dots in it to indicate a lot of impurities that result in a higher resistance. And in the other, the resistor has very few little dots in it, meaning less impurities and a lower resistance. When designing state descriptions, we need to create descriptions that encompass both what changes as a result of the interactive use, as well as what remains unchanged. Let's listen to the state descriptions for Ohm's law. As we do so, listen carefully to the structure of the descriptions and the specific words and phrases. Consider how they each support and encourage interaction. Make note of any questions you have about what's in the state descriptions and the choices we made in the description design. After listening to the state descriptions, head over to the next video, where we'll continue learning more about state descriptions. Let's listen to the state descriptions in the sim starting state. >> Heading level one, Ohm's law. Ohm's law is an interactive sim. It changes as you play with it. It has a play area and a control area. In the play area, you find the equation for Ohm's law, V = I times R in a circuit. Voltage and resistance sliders allow changes to the equation in circuit. In the control area, a button allows users to reset the sim. Right now, list three items. Voltage, V, is 4.5 volts, one of three. Resistance, R, is 500 ohms, two of three. Current, I, is 9.0 milliamps, three of three. End of list. Look for voltage and resistance sliders to play or read on for details about equation and circuit. If needed, check out keyboard shortcuts under sim resources. Heading level two, play area. Heading level three, Ohm's law equation. Voltage, V, is equal to current, I, times resistance, R. In equation, letter V is much, much larger than letter I and comparable to letter R. >> Now, I'm going to turn off my screen reader for a moment to make a few changes. I'm going to increase the voltage to the maximum and decrease the resistance to the minimum. And then I'll turn my screen reader back on to read through the summary play area and control area. That way, everything you hear from the screen reader will be the state descriptions. We'll get to the responsive descriptions. That would be read aloud as I make changes in week four of this course. >> Heading level three, slider controls. Heading level three, the circuit. Heading level three, Ohm's law equation. Heading level two, play area. Heading level one, Ohm's law. Ohm's law is an interactive sim. It changes as you play with it. It has a play area and a control area. In the play area, you find the equation for Ohm's law, V = I times R in a circuit. Voltage and resistance sliders allow changes to the equation in circuit. In the control area, a button allows users to reset the sim. Right now, list three items. Voltage, V, is 9.0 volts, one of three. Resistance, R, is 10 ohms, two of three. Current, I, is 900.0 milliamps, three of three. End of list. Look for voltage and resistance sliders to play or read on for details about equation and circuit. If needed, check out keyboard shortcuts under sim resources. Heading level two, play area. Heading level three, Ohm's law equation. Voltage, V, is equal to current, I, times resistance, R. In equation, letter V is much, much smaller than letter I and much, much larger than letter R. >> Notice how regardless of whether we're listening through the state descriptions of the sim on startup or after making some changes. The state descriptions are always describing the state right now using the active present tense throughout.