To select technologies by type the six filter buttons above the scroll on the right hand side of the screen are used. By clicking on the button labeled “navy” for instance you filter out all technologies except those related to your navy.
Use the three medallions to the side of the right hand scroll to display technologies according to whether you already know them or not. The top medallion displays technology your Empire already knows. The middle medallion displays technology that can currently be researched if you have a vacant research slot. The lower medallion displays technologies that can be picked as goals. Generally, goals are technologies that you cannot learn about right away, but supply a direction for your current research.
The six filter buttons work the same way regardless of which medallion you select. For instance, the army filter shows you army-related technology that you already know, or that you could research, or that could be set as a goal, depending on which medallion you select.
You may click on the small magnifying glass button that appears with each technology to obtain more detail about that development. This can be used to see where a technology will lead you in the future.
