| Ion exchange | (Environmental Engineering) An adsorption process in which one ion is exchanged for another ion of like charge. There is an equivalence of exchanged charge. |
| Irreversible reaction | (Environmental Engineering) A reaction in which the reactant(s) proceed to product(s), but the products react at an appreciable rate to reform reactant(s). |
| Isomers | (Environmental Engineering) Two or more different compounds with the same chemical formula but different structure and characteristics. |
| Independent test group (ITG) - | (Software Engineering) a group of people whose primary responsibility is software testing |
| Interface design - | (Software Engineering) a software engineering action that establishes the structure and workflow for a user interface; follows three "golden rules:" place the user in control, reduce the user's memory leoad, make the interface consistent. |
| Integration testing - | (Software Engineering) a testing step that constructs the software while testing it |
| Integration - | (Software Engineering) the specific approach to integration testing |
| Interoperability - | (Software Engineering) the degree to which one application communicates or interfaces with another |
| ISO 9001:2000 - | (Software Engineering) a quality assurance standard that applies to software engineering |
| Impermeable | (Concrete Engineering) The ability of a material or product to reduce or eliminate gaseous transmissions through it's mass; measured as the rate of Water Vapor Transmission (WVT). Note: Not all materials that are waterproof are vaporproof; all materials that are vaporproof are inherently waterproof. |