How can Parents Embed Language?

Many people think of speech-language pathologists (Speech Therapists or SLPs)as professionals that work with people to improve their speech (also called articulation or fluency), but a big piece of SLPs job is to help children with language development. Language is so important for individuals to function in school and life. When children have a developmental delay that impedes their ability to effectively communicate, SLPs work with parents, teachers and other caregivers to develop strategies that improve language acquisition.

Children learn language and communication from their environment and from their experiences and interactions with the people in their environment. Studies have shown that on average, about 90% of the words used by children by the age of three come from their parents’ vocabularies. Children imitate the number of words spoken, the length of conversations and the speech patterns of their caregivers.

This is why it is so important for parents and caregivers to actively engage their infants and children by talking to them as much as possible. The number of words a child hears per day will greatly impact their vocabulary and their language development, and ultimately this impacts success in many other areas for children as they develop. It does not need to be complicated- simply noticing your environment and commenting on it to your child is all it takes to stimulate your child’s learning of language and communication. It’s the frequency that matters.

One of the easiest ways to encourage the learning of language and communication is by encouraging talking during your normal, daily routines. Activities such as bathing, dressing, mealtimes, cooking, doing laundry, going for a walk, driving in the car, and grocery store shopping are all typical daily routines and activities during which you can embed all kinds of important skills that we want kids to learn (see reverse for 10specific ideas).

Below are ten specific skills related to language development with examples of how to insert those into daily activities:
1. Joint Attention Skills:

When looking at pictures, reading books, or even just playing with children, it is important that the child looks at the object, picture, or toy that you are talking about. This ensures that the child is listening and is able to understand the object or picture being labeled and described.

2. Turn-Taking:

Teaching children to respond to physical and verbal directions sets the stage for understanding how to share between two people. For example, when playing with a toy car, if the parent pushes the car to the child and says “vroom-vroom”, the parent waits for the child to respond by pushing the toy car back to them and imitating the sound.

3. Language Stimulation:

During all kinds of daily activities, talk to your child about what you are doing, seeing, hearing, etc. in your environment.

4. Play Skills:

Through play, children often show us what they understand about the world. This is how children discover and learn about objects, people and the world around them. Play with your child often and talk as you play about what you are doing.

5. Fill in the blank:

Set up a predictable, language routines, for example, set up a familiar phrase and purposefully leave out the last word, i.e., While singing “the wheels on the bus go round and ____, round and _____.” Or while reading “brown bear, brown ____.” Gradually make the task more complicated, i.e., during a favorite book, you can exclaim, “Oh, no…look…Clifford is laughing…he feels ____.” Prompt your child by looking at them and waiting for them to reply. Once you do this a few times, they will catch on.

6. Provide choices:

Provide choices instead of asking questions so your child does not have the option of answering “no” when you want to stimulate interaction. Instead of asking your child “Do you want to play with your cars” ask “Do you want to play with your cars or train?”

7. Picture walk: 

It is not necessary to read every word in a book as they can often be too wordy and confusing for the early learner. Instead, encourage your child to look at the pages and guess what is going on. Set up a familiar structure to help your child express herself—go through the book and point out familiar nouns/verbs using the phrase, “I see___”… “I see a puppy.” “I see a sun” while pointing to the object. Next, take your child’s finger and put it on an object you are sure he/she is familiar with and use the fill in the blank procedure “I see a _____ (CAT!)”.When your child becomes familiar with the routine, he/she will begin to say the phrase by herself. This sets up the routine of “my turn-your turn”.

8. Out of reach:

Put desired objects in out of reach places to encourage your child to request and ask for help. A natural instinct for parents is to make everything easier for their child—but many times we are actually doing a disservice when we anticipate our child’s every need. Once a child realizes the power of language, they will talk for what they want.

9. Confusion:

This can get your child talking and it is a nice time to introduce early language concepts in a very concrete way. So—the next time you are at the table and your child asks for peanut butter—give him regular butter instead. Wait for him to tell you that this isn’t what he asked for—at that point you can say “But, Didn’t you ask for butter?”—“NO! PEANUT butter mommy!”—“Oh, I get it now. Peanutbutter and butter are the same in a lot of ways—we can spread both of them on bread, they are both soft and they both have the word “butter” in them! But, they are also very different…peanut butter is a darker color—more like a light brown—and it is sweeter.”

10. Ask and then, Listen:

Once your toddler is talking, start teaching them to initiate conversations, and listen, a lot. You will be surprised once you stop talking about how much more your toddler will talk. This will give your child an opportunity to practice initiating communication and then you can let your child take the lead. Initiating conversation lays the groundwork for many social skills that are so important for future development.

-by Amy Hill, M.A., CCC-SLP and Ronit Molko, Ph.D., BCBA-D

Addressing Aggressive Behaviors in Children

Aggressive behavior is something that parents of children with autism or emotional disabilities are often confronted with on a regular basis. It can be a challenging, frustrating and emotionally draining experience. Through the support of a professional behavior analyst and consistent practices, parents, teachers, and caregivers can address aggressive behaviors in children and adolescents so that they can live productive and independent lives.

Many times when caregivers are faced with aggressive behavior, their impulse is to want to stop the behavior, and they may view the child as misbehaving. However, it’s important to understand that aggressive behavior is sending us a message. Every behavior serves a function— such as making a request, avoiding something, escaping a task or seeking attention. The same is true of aggression. For individuals with limited communication skills, aggressive behaviors can become inadvertently shaped by caretakers and others in their environment.

For example, a child throws a tantrum to gain access to candy. The parent gives the child candy to stop the tantrum. If this interaction repeats itself, the behaviors become reinforced and the child learns that tantruming is rewarded with access to the desired food. Next time, the parent may decide they are not going to give the child candy and so the child tantrums even louder and harder. If the parent gives the child candy, the parent has inadvertently reinforced the behavior. As parents, we all do this in very subtle ways regardless of whether our child has special needs or not, often without realizing that we are shaping our children’s behavior and strengthening the behaviors that are unwanted.

When children are small, it can be less of an issue for parents to manage aggression, or they may think that their child will grow out of it. It is easier to restrain young kids to combat and control outbursts, but if these are the only methods we use, we are not setting our teenagers up for success. It is important to understand why our kids are acting out and what they are trying to communicate. Once we know the “what” and the “why”, we can teach more appropriate means of communication to replace the need for aggression (such as making a verbal request and teaching the child to tolerate “no” when the answer is “no”). If the aggressive behaviors are not replaced by more appropriate functional behaviors, then we run the risk of shaping adolescent aggression which can include physical violence that is more serious and tougher to overcome.

If your child is demonstrating aggression, the best place to start is an assessment of his behavior to understand why the behaviors are occurring. A good assessment will tell you what the function of the behavior is, meaning— why he is acting out and what he is trying to communicate. Then a plan can be put in place to teach new methods for communicating effectively as well as reducing and eliminating the aggression using behavioral strategies.

Here are a few strategies you can use before aggressive episodes start:

  1. Give up some control over the environment or routines by offering choices; it does not matter if he brushes his teeth before changing clothes, but if having control over that routine helps keep your child’s aggression down, give up that control and let him choose. Providing choice also teaches independent thinking and problem solving which are critical skills for adult life.
  2. Prime your child by giving them a verbal “heads up” of what is coming: describe to your child when and what the expectations are for that setting.
  3. Use visual support like a picture board or a photo to help provide clear expectations for each activity or different parts of the day.
  4. Prompt and model the behavior you want to see instead of the aggressive behavior.
  5. Praise that behavior when you do see it so that it will continue to be a part of their repertoire. Remember if you like something you need to let your child know. In other words, catch them being good and if you like a behavior, reinforce it!

In the moment of the aggressive behavior, safety is most important! Do your best to keep yourself and your child safe. If you can redirect your child onto something else or an activity, that might be necessary.

Some parents of adolescents who display aggressive behaviors worry that it is too late for their child to have a fulfilling and independent life. On the contrary, it is never too late to start planning on a future for your child and working towards attainable goals. Think about what you want your child to be doing in a year from now and start working towards that today. If you want your child to ask for the desired item or preferred activity instead of tantruming to get it, start taking small steps now. If you are hoping they will have more friends in a year, start exposing your child to those opportunities and teaching the socially appropriate skills that will afford those opportunities. If you want them to have fewer aggressive behaviors, do not wait a year to start working to improve that behavior. It is never too late or too early to start working towards next year. The results will support your child in having their needs met and experiencing greater success at each stage of development. The ultimate goal is setting your child up for success and helping him achieve as much independence as possible.

-Richie Ploesch, M.A., BCBA, and Ronit Molko, Ph.D., BCBA-D

The Benefits of ABA in Dual Environments

When a child is diagnosed with autism, parents become charged with finding quality treatment – and the evidence-based recommendation is to seek out Applied Behavior Analysis (ABA).  Choosing the specific ABA program that is right for a child can feel daunting, especially if ABA is new territory for a family.  In this article, we look at the benefits of a program incorporating both in-home and center-based programs.

Many proponents of ABA like to state, “ABA can be done anywhere.” It is true – but we shouldn’t overlook another important point: the environment itself is a critical component of therapy.  Controlling the environment to some degree is frequently part of the teaching process.  Selecting a teaching environment is a decision that impacts the rest of the teaching strategy and so also has an effect on progress.

Common teaching environments for young children with autism include center-based ABA therapy, private or public school, a childcare environment, and home programs.   While there is not enough research to prescribe a particular environment or model generally for children with autism, many parents and professionals are finding that a multi-site model of a controlled environment (such as a center-based program) and a natural environment (home, childcare, school) provides the best of both worlds.

Benefit #1 – Social skills can be targeted consistently and with children in the child’s community.

It is necessary for peers to be available regularly for consistent teaching; in this respect, a clinic setting is ideal for having regular access to other children to practice target skills.  Ultimately, the goal is for the child to interact with the other children in their community, their siblings, classmates, and neighbors.  Having a regular home component allows the therapist to work on target skills with the people who will be important in their normal daily life, even if these opportunities aren’t as regular as those in a clinic setting.

Benefit #2 – Controlled Environment vs. Natural Environment: Best of both worlds

A multi-site model allows technicians to address the most challenging skills in a distraction-free environment, but still have access to the home or school setting, with all of its naturally-occurring distractions, to make sure that those learned skills are being put to use.

Benefit #3 – Consistency of the Behavior Plan

When a challenging behavior is treated differently across settings, it is more likely to persist; this set-up can even make the behavior worse in the long-run.  The best treatment involves the same plan being followed across the day.  Having professionals use a consistent plan in both the home and center environments also supports family members to do the same.

Benefit #4 – Assessment of Generalization

All programs must address the issue of generalization, but a multi-site model is tailor-made for this.  Generalization can be specifically addressed right from the beginning, either by teaching in both environments, or by teaching in one place and testing generalization in the other.

Benefit #5 – Ease of Group Work Vs. Ease of Parent Training – You Get Both!

One of the most important aspects of the teaching environment is the people present.  In a center-based program, other children are close at hand for social interactions, peer modeling, and working on group instruction, so these parts of therapy can happen regularly.  When ABA sessions are at home, it can be more convenient for parents to make themselves available for training.  In a multi-site model, the child benefits from both of these types of teaching opportunities.

Whichever provider a family selects, they should be sure to work closely with their team to personalize the child’s program to best meet their needs and the goals for their family.

– Richie Ploesch, M.A., BCBA & Katherine Johnson, BCBA

A New Year to Make Progress 2019

We are happy to re-share this blog from a previous year that received so much wonderful feedback. We wish everyone a year of great moments, memories and progress.

Autism is in the news, social media, and print more than ever. The increasing awareness is great. The influx of research and funding options is even better! The heartwarming stories and success stories are inspiring. Still, misinformation and slanted headlines are annoyingly abound. Such is this complicated, passionate and ultimately very unique autism community. We are glad to be a part of it, and do our best to honor and respect the many contributing voices. As a community, we are making progress and continue to be optimistic that together, we can make great strides. We have no doubt that the most important person to each and every parent, day-in and day-out, is your child with autism.

So what will this year’s 365 days mean for you? We suggest this simple, but powerful idea: progress. When you’re past the notion that there may be a quick fix and come to terms that the pursuit of a cure won’t help you with today’s challenges, progress is the name of the game. Forget quantum leaps; each milestone met will offer its own reward. Know there will be set backs and rough patches, and keep moving forward.

BE PRESENT: There are many amazing therapists, doctors and teachers in the world who have taught so much about development and parenting. However, keep in mind that you are the one who is with your child every day. For real progress to take place, you gotta be in the game. Don’t forget to take time to just BE with your child and appreciate all the beautiful, unique ways they express themselves.

BE CONSISTENT: What is the 12 step motto…”the more you work it, the more it works”? Working consistently with your child’s team to implement strategies, even when it’s hard or inconvenient, propels the process.

BE A FRIEND/SPOUSE/PERSON: You can’t focus on autism 24 hours a day. Remember to make time for yourself, friends and family. When you do, life just has more balance and you’ll likely have more stamina for the work ahead.

BE GRATEFUL: Count your blessings, celebrate the wins and enjoy every single bit of progress. This is what makes it all worth it. No one else will feel joy quite the way you will. It’s awesome.

This year, we will continue to be moved, enlightened and sometimes annoyed by it all. Stick to a plan that works for you and your family, and know that come December 31, 2019, you’ll be able to look at another year passed – and call it good.

For great news and information, visit our blog, All Autism Videos and All Autism Talk.

Preparing for Holiday Meals

The holidays are quickly approaching, which means family, festivities, and food! While the holidays can be fun for the whole family, they can also be a stressful time for children on the autism spectrum due to the changes in typical routines and settings. Holiday meals with extended family can present issues for a child with autism, including trying new foods, sitting among loud family members, and being in an unfamiliar location. Here are some helpful tips to make the holiday experience more enjoyable for the whole family.

Prepare your child for the event.
Use photos, a social story, or show them a video, modeling what will be expected of them. Will they need to sit at a communal table surrounded by family? Will they be expected to try new foods? How about preparing your child for the family members who will be present? You can practice with role play at home with real or fake food so your child is familiar with the expectation of the meal. To make it easier this time of year, you can also bring some favorite foods along that you know will be successful.

Support them during the event.
Bring activities and toys so your child has something to do while waiting for the meal to begin. If your child is very picky with food, bring some preferred alternatives that they will eat so they don’t become agitated while waiting and to remind your child of familiar food routines.

Give them a chance to escape if they need it.
If your child becomes overstimulated by loud noises or holiday lights and decorations, find a quiet place in the home for them to decompress and take a break. Your child can rejoin the family once he or she feels comfortable doing so.

While holiday meals can be stressful, hopefully these tips will help keep everyone’s spirits bright!

 

– Sarah Low, M.A., BCBA

10 Tips for Navigating the IEPs

The Outcome of your IEP process relies on you…

One of the most important discussions parents can have with their clinical team is about the goals they have for their child as they grow into adulthood. Most parents grapple with finding the time to think about their child’s long-term future when they are facing the daily needs of mealtimes, sleep schedules, or having a successful play-date. However, as tough as this discussion is, it is critically important to start this conversation early because the foundational skills that will enable your child to function well as an adult are taught and acquired during childhood.

A significant part of a child’s development will be determined by their school environment, academic placement, and the academic curriculum that guides their learning. A child’s initial Individual Education Plan (IEP) is critical. This important document will lay the groundwork for the types and level of services that a child will receive throughout their academic years. It is essential that parents put sufficient time and effort into preparing for their first and subsequent IEP meetings.

An Individual Education Plan (IEP) is a legal document that is developed for every child eligible for special education. This plan contains a statement of a child’s present level of functioning in terms of performance, educational needs, goals, levels of service, and measurable outcomes. The first IEP meeting is typically held before a child transitions into preschool or as soon as a child is identified as having a special need and determined eligible for special education services. An IEP meeting can be held at multiple times during the year: after a formal assessment; if a child demonstrates a lack of progress; or if a parent or teacher requests a meeting to develop, review, or revise a child’s current IEP.

There are some important steps that parents should consider when beginning the IEP process. We have outlined some of the most important ones for you here. The following guidelines can help you prepare for your first IEP:

  1. Understand the IEP Process and Know Your Rights. It is of paramount importance to read up on the IEP process, become familiar with IDEA (Individuals with Disabilities Education Act), and understand your rights as a parent. In addition to studying the law, many parents seek advice from an advocate and network with well-informed parents who have first-hand experience with the IEP process in their school district.
  2. Make All of Your Requests in Writing. All requests should be made in writing to create a documentation trail that provides a history of the child’s academic needs and requests to the school district (e.g., requests for an IEP meeting, an assessment of any kind, or a classroom placement recommendation). It also allows you to state your requests in your own words. In addition, ask the IEP committee to record these written requests as part of the minutes in an IEP meeting. The IEP committee can accept or deny these requests. If the committee denies the requests, then they must follow the procedural safeguards in IDEA and provide written notice of why they are denying your request. If the request is not documented in writing, the school district is not required to provide the service. (Be Familiar with Prior Notice of the Procedural Safeguards (34 CFR 300.503))
  3. Obtain Independent Assessments Ahead of Your IEP Meeting. The school team should not be recommending nor denying services without an assessment to evaluate the need for that service and neither should parents. You will want to request, in writing, that your child be assessed before the IEP meeting is held. Ideally, if all the necessary assessments are conducted prior to the IEP meeting, then the recommendations for treatments can be discussed during the IEP meeting. Be sure to request copies of the assessments, progress reports, and proposed goals in advance of the meeting, in order to have ample time to review and be fully informed during the meeting.
  4. Organize All of Your Records. Parents should have all of their records on hand and easily accessible during IEP meetings. Create a system of storing and updating all information that makes sense to you and that makes it easy for you to find the information you need.
  5. Observe the Classroom. Ask to observe any classroom where your child is being recommended for placement, so you can better understand if it would be a good fit. If for some reason the school will not let you observe, have a professional who is familiar with your child observe the setting.The law states that the team must start with the Least Restrictive Environment (LRE) which is the general education classroom as the first option and work towards a more restrictive environment only as necessary as needs come up that cannot be met with supports and modifications in the LRE. Therefore, placement should never be decided upon before the child’s goals and objectives are concluded. (see item #7 for Goals and Objectives)
  6. Formulate a list of Questions before your IEP. In advance of the meeting, prepare a comprehensive list of questions (a very long list is completely appropriate). During the meeting, assign someone on your team to take notes and write down answers to all of your questions. This allows you to focus on the conversation. A tremendous amount of information is exchanged at IEP meetings, and it can be overwhelming to absorb it all.
  7. Make Sure Goals and Objectives are Progress Oriented. Goals and objectives are one of the most important elements of an IEP. If the goals and objective are not written in a manner that is observable and measurable, one cannot determine if a child is making progress. Without this, the school can claim that a child has made progress without producing actual data to evidence the skills gained. In addition, the goals and objectives will specify what a child needs to learn in that academic year. This is the critical time to think more long-term. Will these goals serve where you want your child to be two years from now? Five years from now? Are they laying the foundation for the necessary skills that your child will need as an adult to live the most independent life he or she can? Get input from members of the team that work with your child before the meeting; ask for their opinion of your child’s progress and needs.
  8. Be the Host, Not the Guest. Since IEP meetings are held at the school district, parents typically feel like a guest at their child’s IEP. However, since the IEP meeting is about your child, parents can create a more personal atmosphere. For example: by providing snacks, pastries and light refreshments, you can put yourself in the position of host of the IEP meeting. Another idea is to bring a photograph of your child and place it in the center of the table to remind the team who and what the meeting is about- providing services to support this specific child in attaining his or her highest potential.
  9. Never Go Alone. The support of a family member, uncle, husband, friend, advocate, cannot be overstated. The IEP process can be  stressful, tiring, and sometimes overwhelming. Parents often share that having someone else in the room to support them, take notes and offer reassurance makes a huge difference. In some instances, parents obtain professional support from advocates or special education attorneys who specialize in the IEP process.
  10. Disagree Without Being Disagreeable. Once the team has made their recommendations and concluded the IEP, parents will be asked to sign the IEP document. The IEP document allows for them to sign that they were present at the IEP but that they do not agree at that time with the recommendations. This is a good option to exercise at the end of the meeting. It gives you the opportunity to take the IEP home to review later and have the option to request changes. This can be done in a very respectful way, allowing you time to make the best decisions that are best for your family.As a parent, you are a vital part of your child’s IEP team. You are your child’s best advocate and the person who knows what’s best and most appropriate for him. With the correct information and support you can create a comprehensive and suitable roadmap for your child’s future.

 

– Michelle Stone, M.S., BCBA. Based on an interview with David Wyles- a Parent’s Guide to the IEP.

Beyond Picky Eating – Addressing Your Child’s Feeding Issues

Feeding is part of our daily life. Most people eat at least three times per day and mealtime is typically a pleasant experience; however, for children with feeding problems, this daily routine can become an aversive situation for children and their caregivers. 

Studies suggest the majority of children with autism have some type of a feeding problem (Volkert & Vaz, 2010). Feeding problems can include complete food refusal, disruptive mealtime behaviors, inappropriate pace of eating, lack of self-feeding skills, and “picky eating,” as caregivers often refer to it.

“Picky eating” may consist of a variety of selective feeding behaviors such as only eating foods of certain textures (e.g., crunchy, pureed), brands (e.g., from a particular restaurant), types (e.g., meat, starches), or colors.  When a child does not eat enough or does not eat a wide enough variety of foods, there may be significant medical implications (e.g., weight loss, malnutrition, poor growth) or social implications (e.g., not eating with peers, at family gatherings, or at restaurants). Children with feeding problems can create additional burdens on caregivers if caregivers need to prepare a separate meal for one family member, bring special food on community outings, or decline attending social events in fear of how their child may behave when presented with novel foods.

Extensive research has been conducted in the field of applied behavior analysis on feeding interventions for children with and without autism. Like any behavioral intervention, feeding interventions are specifically tailored to a child and his/her family to produce the best possible outcomes. An intervention that works for one child may not work for another. Additionally, there are several reasons why a child may not be eating and these reasons will vary from child to child. It is important to assess why a child is not eating (i.e., a medical or behavioral reason) before beginning an intervention. Feeding problems can involve many complex factors, and interventions to help children with feeding problems are by no means a one-size-fits-all situation.  This is when the help of specialists is crucial. Often, feeding interventions consist of a team of specialists which may include doctors, occupational therapists, speech therapists, nutritionists, and Board Certified Behavior Analysts. Caregivers, being a specialist in their child, are also a vital part of the feeding intervention team.

Caregivers may be resistant to feeding interventions and may have negative perceptions of what feeding interventions entail. Some may think feeding interventions consist of extremely aversive procedures, such as forcing a child to eat; however, there are several less intrusive interventions that have demonstrated successful results for a number of children.

Some interventions simply alter what is done before a meal begins to increase the likelihood that a child will eat (e.g., telling the child, “first dinner, then dessert,” creating a dinnertime routine, mixing a non-preferred food with a preferred food). Some children respond well to these less intrusive strategies, but some children require more intensive feeding interventions (Seubert, Fryling, Wallace, Jiminez, & Meier, 2014). Depending on the severity of the feeding problem, a feeding intervention can be a challenging and lengthy process; however, after a feeding intervention has been successfully implemented, the once unpleasant mealtime can become an enjoyable experience for both the child and his/her family.

In my own experience working with clients, I have had the opportunity to see many of the rewarding effects of feeding interventions. Here are a few examples of successes that can be achieved through intervention:

A child who only ate pureed foods received intensive intervention and began to eat the same meal as his family, smiling and laughing in the process. Another family could not eat at a restaurant because their child would scream, cry, and refuse to eat restaurant food; after slightly modifying their restaurant routine, the family could enjoy a relaxing meal together at a restaurant with their child eating food the restaurant served.

One particular selective eater refused to eat anything except chicken, which limited his ability to attend social events; more foods were slowly introduced to this child’s diet and eventually, he was able to eat many foods that were previously refused, including enjoying pizza and cake at a friend’s birthday party.  Growth and weight are a common concern of parents. I have seen a child who regularly refused to eat and was completely below the growth chart; after training her parents on a feeding intervention, she steadily gained weight and is now back on the growth chart and continuing to grow. It is important to keep in mind that all interventions are individualized, but these are just a few examples of the positive changes the right team and the right intervention can have for children and their families.

It is remarkable to see this difficult, daily routine become an enjoyable experience for those involved. Effective intervention for feeding problems can truly change the quality of life for our families.

If you have concerns about your child’s eating or food selection, speak to your child’s pediatrician.

 

Christine Seubert, M.S., BCBA

 

Seubert, C., Fryling, M. J., Wallace, M. D., Jiminez, A. R., and Meier, A. E. (2014). Antecedent interventions for pediatric feeding problems. Journal of Applied Behavior Analysis, 47,449-453.

Volkert, V. M. & Vaz, P. C. M. (2010). Recent studies on feeding problems in children with autism. Journal of Applied Behavior Analysis, 43,155-159.